diff options
| -rw-r--r-- | drivers/net/wireless/iwlwifi/iwl3945-base.c | 215 | ||||
| -rw-r--r-- | drivers/net/wireless/iwlwifi/iwl4965-base.c | 212 |
2 files changed, 356 insertions, 71 deletions
diff --git a/drivers/net/wireless/iwlwifi/iwl3945-base.c b/drivers/net/wireless/iwlwifi/iwl3945-base.c index ba5146ffdf4..71e9b7c52d5 100644 --- a/drivers/net/wireless/iwlwifi/iwl3945-base.c +++ b/drivers/net/wireless/iwlwifi/iwl3945-base.c @@ -63,13 +63,13 @@ static int iwl3945_tx_queue_update_write_ptr(struct iwl3945_priv *priv, ******************************************************************************/ /* module parameters */ -static int iwl3945_param_disable_hw_scan; -static int iwl3945_param_debug; -static int iwl3945_param_disable; /* def: enable radio */ +static int iwl3945_param_disable_hw_scan; /* def: 0 = use 3945's h/w scan */ +static int iwl3945_param_debug; /* def: 0 = minimal debug log messages */ +static int iwl3945_param_disable; /* def: 0 = enable radio */ static int iwl3945_param_antenna; /* def: 0 = both antennas (use diversity) */ -int iwl3945_param_hwcrypto; /* def: using software encryption */ -static int iwl3945_param_qos_enable = 1; -int iwl3945_param_queues_num = IWL_MAX_NUM_QUEUES; +int iwl3945_param_hwcrypto; /* def: 0 = use software encryption */ +static int iwl3945_param_qos_enable = 1; /* def: 1 = use quality of service */ +int iwl3945_param_queues_num = IWL_MAX_NUM_QUEUES; /* def: 8 Tx queues */ /* * module name, copyright, version, etc. @@ -184,17 +184,24 @@ static void iwl3945_print_hex_dump(int level, void *p, u32 len) * * Theory of operation * - * A queue is a circular buffers with 'Read' and 'Write' pointers. - * 2 empty entries always kept in the buffer to protect from overflow. + * A Tx or Rx queue resides in host DRAM, and is comprised of a circular buffer + * of buffer descriptors, each of which points to one or more data buffers for + * the device to read from or fill. Driver and device exchange status of each + * queue via "read" and "write" pointers. Driver keeps minimum of 2 empty + * entries in each circular buffer, to protect against confusing empty and full + * queue states. + * + * The device reads or writes the data in the queues via the device's several + * DMA/FIFO channels. Each queue is mapped to a single DMA channel. * * For Tx queue, there are low mark and high mark limits. If, after queuing * the packet for Tx, free space become < low mark, Tx queue stopped. When * reclaiming packets (on 'tx done IRQ), if free space become > high mark, * Tx queue resumed. * - * The IWL operates with six queues, one receive queue in the device's - * sram, one transmit queue for sending commands to the device firmware, - * and four transmit queues for data. + * The 3945 operates with six queues: One receive queue, one transmit queue + * (#4) for sending commands to the device firmware, and four transmit queues + * (#0-3) for data tx via EDCA. An additional 2 HCCA queues are unused. ***************************************************/ static int iwl3945_queue_space(const struct iwl3945_queue *q) @@ -213,13 +220,21 @@ static int iwl3945_queue_space(const struct iwl3945_queue *q) return s; } -/* XXX: n_bd must be power-of-two size */ +/** + * iwl3945_queue_inc_wrap - increment queue index, wrap back to beginning + * @index -- current index + * @n_bd -- total number of entries in queue (must be power of 2) + */ static inline int iwl3945_queue_inc_wrap(int index, int n_bd) { return ++index & (n_bd - 1); } -/* XXX: n_bd must be power-of-two size */ +/** + * iwl3945_queue_dec_wrap - increment queue index, wrap back to end + * @index -- current index + * @n_bd -- total number of entries in queue (must be power of 2) + */ static inline int iwl3945_queue_dec_wrap(int index, int n_bd) { return --index & (n_bd - 1); @@ -234,12 +249,17 @@ static inline int x2_queue_used(const struct iwl3945_queue *q, int i) static inline u8 get_cmd_index(struct iwl3945_queue *q, u32 index, int is_huge) { + /* This is for scan command, the big buffer at end of command array */ if (is_huge) - return q->n_window; + return q->n_window; /* must be power of 2 */ + /* Otherwise, use normal size buffers */ return index & (q->n_window - 1); } +/** + * iwl3945_queue_init - Initialize queue's high/low-water and read/write indexes + */ static int iwl3945_queue_init(struct iwl3945_priv *priv, struct iwl3945_queue *q, int count, int slots_num, u32 id) { @@ -268,11 +288,16 @@ static int iwl3945_queue_init(struct iwl3945_priv *priv, struct iwl3945_queue *q return 0; } +/** + * iwl3945_tx_queue_alloc - Alloc driver data and TFD CB for one Tx/cmd queue + */ static int iwl3945_tx_queue_alloc(struct iwl3945_priv *priv, struct iwl3945_tx_queue *txq, u32 id) { struct pci_dev *dev = priv->pci_dev; + /* Driver private data, only for Tx (not command) queues, + * not shared with device. */ if (id != IWL_CMD_QUEUE_NUM) { txq->txb = kmalloc(sizeof(txq->txb[0]) * TFD_QUEUE_SIZE_MAX, GFP_KERNEL); @@ -284,6 +309,8 @@ static int iwl3945_tx_queue_alloc(struct iwl3945_priv *priv, } else txq->txb = NULL; + /* Circular buffer of transmit frame descriptors (TFDs), + * shared with device */ txq->bd = pci_alloc_consistent(dev, sizeof(txq->bd[0]) * TFD_QUEUE_SIZE_MAX, &txq->q.dma_addr); @@ -306,6 +333,9 @@ static int iwl3945_tx_queue_alloc(struct iwl3945_priv *priv, return -ENOMEM; } +/** + * iwl3945_tx_queue_init - Allocate and initialize one tx/cmd queue + */ int iwl3945_tx_queue_init(struct iwl3945_priv *priv, struct iwl3945_tx_queue *txq, int slots_num, u32 txq_id) { @@ -313,9 +343,14 @@ int iwl3945_tx_queue_init(struct iwl3945_priv *priv, int len; int rc = 0; - /* allocate command space + one big command for scan since scan - * command is very huge the system will not have two scan at the - * same time */ + /* + * Alloc buffer array for commands (Tx or other types of commands). + * For the command queue (#4), allocate command space + one big + * command for scan, since scan command is very huge; the system will + * not have two scans at the same time, so only one is needed. + * For data Tx queues (all other queues), no super-size command + * space is needed. + */ len = sizeof(struct iwl3945_cmd) * slots_num; if (txq_id == IWL_CMD_QUEUE_NUM) len += IWL_MAX_SCAN_SIZE; @@ -323,6 +358,7 @@ int iwl3945_tx_queue_init(struct iwl3945_priv *priv, if (!txq->cmd) return -ENOMEM; + /* Alloc driver data array and TFD circular buffer */ rc = iwl3945_tx_queue_alloc(priv, txq, txq_id); if (rc) { pci_free_consistent(dev, len, txq->cmd, txq->dma_addr_cmd); @@ -334,8 +370,11 @@ int iwl3945_tx_queue_init(struct iwl3945_priv *priv, /* TFD_QUEUE_SIZE_MAX must be power-of-two size, otherwise * iwl3945_queue_inc_wrap and iwl3945_queue_dec_wrap are broken. */ BUILD_BUG_ON(TFD_QUEUE_SIZE_MAX & (TFD_QUEUE_SIZE_MAX - 1)); + + /* Initialize queue high/low-water, head/tail indexes */ iwl3945_queue_init(priv, &txq->q, TFD_QUEUE_SIZE_MAX, slots_num, txq_id); + /* Tell device where to find queue, enable DMA channel. */ iwl3945_hw_tx_queue_init(priv, txq); return 0; @@ -346,8 +385,8 @@ int iwl3945_tx_queue_init(struct iwl3945_priv *priv, * @txq: Transmit queue to deallocate. * * Empty queue by removing and destroying all BD's. - * Free all buffers. txq itself is not freed. - * + * Free all buffers. + * 0-fill, but do not free "txq" descriptor structure. */ void iwl3945_tx_queue_free(struct iwl3945_priv *priv, struct iwl3945_tx_queue *txq) { @@ -367,19 +406,21 @@ void iwl3945_tx_queue_free(struct iwl3945_priv *priv, struct iwl3945_tx_queue *t if (q->id == IWL_CMD_QUEUE_NUM) len += IWL_MAX_SCAN_SIZE; + /* De-alloc array of command/tx buffers */ pci_free_consistent(dev, len, txq->cmd, txq->dma_addr_cmd); - /* free buffers belonging to queue itself */ + /* De-alloc circular buffer of TFDs */ if (txq->q.n_bd) pci_free_consistent(dev, sizeof(struct iwl3945_tfd_frame) * txq->q.n_bd, txq->bd, txq->q.dma_addr); + /* De-alloc array of per-TFD driver data */ if (txq->txb) { kfree(txq->txb); txq->txb = NULL; } - /* 0 fill whole structure */ + /* 0-fill queue descriptor structure */ memset(txq, 0, sizeof(*txq)); } @@ -392,6 +433,11 @@ const u8 iwl3945_broadcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF /**************************************************************/ #if 0 /* temporary disable till we add real remove station */ +/** + * iwl3945_remove_station - Remove driver's knowledge of station. + * + * NOTE: This does not remove station from device's station table. + */ static u8 iwl3945_remove_station(struct iwl3945_priv *priv, const u8 *addr, int is_ap) { int index = IWL_INVALID_STATION; @@ -428,6 +474,12 @@ out: return 0; } #endif + +/** + * iwl3945_clear_stations_table - Clear the driver's station table + * + * NOTE: This does not clear or otherwise alter the device's station table. + */ static void iwl3945_clear_stations_table(struct iwl3945_priv *priv) { unsigned long flags; @@ -440,7 +492,9 @@ static void iwl3945_clear_stations_table(struct iwl3945_priv *priv) spin_unlock_irqrestore(&priv->sta_lock, flags); } - +/** + * iwl3945_add_station - Add station to station tables in driver and device + */ u8 iwl3945_add_station(struct iwl3945_priv *priv, const u8 *addr, int is_ap, u8 flags) { int i; @@ -486,6 +540,7 @@ u8 iwl3945_add_station(struct iwl3945_priv *priv, const u8 *addr, int is_ap, u8 station->used = 1; priv->num_stations++; + /* Set up the REPLY_ADD_STA command to send to device */ memset(&station->sta, 0, sizeof(struct iwl3945_addsta_cmd)); memcpy(station->sta.sta.addr, addr, ETH_ALEN); station->sta.mode = 0; @@ -504,6 +559,8 @@ u8 iwl3945_add_station(struct iwl3945_priv *priv, const u8 *addr, int is_ap, u8 le16_to_cpu(station->sta.rate_n_flags); spin_unlock_irqrestore(&priv->sta_lock, flags_spin); + + /* Add station to device's station table */ iwl3945_send_add_station(priv, &station->sta, flags); return index; @@ -673,6 +730,8 @@ static int iwl3945_enqueue_hcmd(struct iwl3945_priv *priv, struct iwl3945_host_c fix_size, q->write_ptr, idx, IWL_CMD_QUEUE_NUM); txq->need_update = 1; + + /* Increment and update queue's write index */ q->write_ptr = iwl3945_queue_inc_wrap(q->write_ptr, q->n_bd); ret = iwl3945_tx_queue_update_write_ptr(priv, txq); @@ -1511,7 +1570,7 @@ static void get_eeprom_mac(struct iwl3945_priv *priv, u8 *mac) /** * iwl3945_eeprom_init - read EEPROM contents * - * Load the EEPROM from adapter into priv->eeprom + * Load the EEPROM contents from adapter into priv->eeprom * * NOTE: This routine uses the non-debug IO access functions. */ @@ -1536,6 +1595,7 @@ int iwl3945_eeprom_init(struct iwl3945_priv *priv) return -ENOENT; } + /* Make sure driver (instead of uCode) is allowed to read EEPROM */ rc = iwl3945_eeprom_acquire_semaphore(priv); if (rc < 0) { IWL_ERROR("Failed to acquire EEPROM semaphore.\n"); @@ -2631,21 +2691,23 @@ static void iwl3945_build_tx_cmd_basic(struct iwl3945_priv *priv, cmd->cmd.tx.next_frame_len = 0; } +/** + * iwl3945_get_sta_id - Find station's index within station table + */ static int iwl3945_get_sta_id(struct iwl3945_priv *priv, struct ieee80211_hdr *hdr) { int sta_id; u16 fc = le16_to_cpu(hdr->frame_control); - /* If this frame is broadcast or not data then use the broadcast - * station id */ + /* If this frame is broadcast or management, use broadcast station id */ if (((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA) || is_multicast_ether_addr(hdr->addr1)) return priv->hw_setting.bcast_sta_id; switch (priv->iw_mode) { - /* If this frame is part of a BSS network (we're a station), then - * we use the AP's station id */ + /* If we are a client station in a BSS network, use the special + * AP station entry (that's the only station we communicate with) */ case IEEE80211_IF_TYPE_STA: return IWL_AP_ID; @@ -2656,11 +2718,12 @@ static int iwl3945_get_sta_id(struct iwl3945_priv *priv, struct ieee80211_hdr *h return sta_id; return priv->hw_setting.bcast_sta_id; - /* If this frame is part of a IBSS network, then we use the - * target specific station id */ + /* If this frame is going out to an IBSS network, find the station, + * or create a new station table entry */ case IEEE80211_IF_TYPE_IBSS: { DECLARE_MAC_BUF(mac); + /* Create new station table entry */ sta_id = iwl3945_hw_find_station(priv, hdr->addr1); if (sta_id != IWL_INVALID_STATION) return sta_id; @@ -2746,6 +2809,8 @@ static int iwl3945_tx_skb(struct iwl3945_priv *priv, spin_unlock_irqrestore(&priv->lock, flags); hdr_len = ieee80211_get_hdrlen(fc); + + /* Find (or create) index into station table for destination station */ sta_id = iwl3945_get_sta_id(priv, hdr); if (sta_id == IWL_INVALID_STATION) { DECLARE_MAC_BUF(mac); @@ -2767,30 +2832,52 @@ static int iwl3945_tx_skb(struct iwl3945_priv *priv, __constant_cpu_to_le16(IEEE80211_SCTL_FRAG)); seq_number += 0x10; } + + /* Descriptor for chosen Tx queue */ txq = &priv->txq[txq_id]; q = &txq->q; spin_lock_irqsave(&priv->lock, flags); + /* Set up first empty TFD within this queue's circular TFD buffer */ tfd = &txq->bd[q->write_ptr]; memset(tfd, 0, sizeof(*tfd)); control_flags = (u32 *) tfd; idx = get_cmd_index(q, q->write_ptr, 0); + /* Set up driver data for this TFD */ memset(&(txq->txb[q->write_ptr]), 0, sizeof(struct iwl3945_tx_info)); txq->txb[q->write_ptr].skb[0] = skb; memcpy(&(txq->txb[q->write_ptr].status.control), ctl, sizeof(struct ieee80211_tx_control)); + + /* Init first empty entry in queue's array of Tx/cmd buffers */ out_cmd = &txq->cmd[idx]; memset(&out_cmd->hdr, 0, sizeof(out_cmd->hdr)); memset(&out_cmd->cmd.tx, 0, sizeof(out_cmd->cmd.tx)); + + /* + * Set up the Tx-command (not MAC!) header. + * Store the chosen Tx queue and TFD index within the sequence field; + * after Tx, uCode's Tx response will return this value so driver can + * locate the frame within the tx queue and do post-tx processing. + */ out_cmd->hdr.cmd = REPLY_TX; out_cmd->hdr.sequence = cpu_to_le16((u16)(QUEUE_TO_SEQ(txq_id) | INDEX_TO_SEQ(q->write_ptr))); - /* copy frags header */ + + /* Copy MAC header from skb into command buffer */ memcpy(out_cmd->cmd.tx.hdr, hdr, hdr_len); - /* hdr = (struct ieee80211_hdr *)out_cmd->cmd.tx.hdr; */ + /* + * Use the first empty entry in this queue's command buffer array + * to contain the Tx command and MAC header concatenated together + * (payload data will be in another buffer). + * Size of this varies, due to varying MAC header length. + * If end is not dword aligned, we'll have 2 extra bytes at the end + * of the MAC header (device reads on dword boundaries). + * We'll tell device about this padding later. + */ len = priv->hw_setting.tx_cmd_len + sizeof(struct iwl3945_cmd_header) + hdr_len; @@ -2802,15 +2889,20 @@ static int iwl3945_tx_skb(struct iwl3945_priv *priv, else len_org = 0; + /* Physical address of this Tx command's header (not MAC header!), + * within command buffer array. */ txcmd_phys = txq->dma_addr_cmd + sizeof(struct iwl3945_cmd) * idx + offsetof(struct iwl3945_cmd, hdr); + /* Add buffer containing Tx command and MAC(!) header to TFD's + * first entry */ iwl3945_hw_txq_attach_buf_to_tfd(priv, tfd, txcmd_phys, len); if (!(ctl->flags & IEEE80211_TXCTL_DO_NOT_ENCRYPT)) iwl3945_build_tx_cmd_hwcrypto(priv, ctl, out_cmd, skb, 0); - /* 802.11 null functions have no payload... */ + /* Set up TFD's 2nd entry to point directly to remainder of skb, + * if any (802.11 null frames have no payload). */ len = skb->len - hdr_len; if (len) { phys_addr = pci_map_single(priv->pci_dev, skb->data + hdr_len, @@ -2818,13 +2910,16 @@ static int iwl3945_tx_skb(struct iwl3945_priv *priv, iwl3945_hw_txq_attach_buf_to_tfd(priv, tfd, phys_addr, len); } - /* If there is no payload, then only one TFD is used */ if (!len) + /* If there is no payload, then we use only one Tx buffer */ *control_flags = TFD_CTL_COUNT_SET(1); else + /* Else use 2 buffers. + * Tell 3945 about any padding after MAC header */ *control_flags = TFD_CTL_COUNT_SET(2) | TFD_CTL_PAD_SET(U32_PAD(len)); + /* Total # bytes to be transmitted */ len = (u16)skb->len; out_cmd->cmd.tx.len = cpu_to_le16(len); @@ -2854,6 +2949,7 @@ static int iwl3945_tx_skb(struct iwl3945_priv *priv, iwl3945_print_hex_dump(IWL_DL_TX, (u8 *)out_cmd->cmd.tx.hdr, ieee80211_get_hdrlen(fc)); + /* Tell device the write index *just past* this latest filled TFD */ q->write_ptr = iwl3945_queue_inc_wrap(q->write_ptr, q->n_bd); rc = iwl3945_tx_queue_update_write_ptr(priv, txq); spin_unlock_irqrestore(&priv->lock, flags); @@ -3329,11 +3425,11 @@ static void iwl3945_txstatus_to_ieee(struct iwl3945_priv *priv, } /** - * iwl3945_tx_queue_reclaim - Reclaim Tx queue entries no more used by NIC. + * iwl3945_tx_queue_reclaim - Reclaim Tx queue entries already Tx'd * - * When FW advances 'R' index, all entries between old and - * new 'R' index need to be reclaimed. As result, some free space - * forms. If there is enough free space (> low mark), wake Tx queue. + * When FW advances 'R' index, all entries between old and new 'R' index + * need to be reclaimed. As result, some free space forms. If there is + * enough free space (> low mark), wake the stack that feeds us. */ static int iwl3945_tx_queue_reclaim(struct iwl3945_priv *priv, int txq_id, int index) { @@ -3382,6 +3478,9 @@ static int iwl3945_is_tx_success(u32 status) * Generic RX handler implementations * ******************************************************************************/ +/** + * iwl3945_rx_reply_tx - Handle Tx response + */ static void iwl3945_rx_reply_tx(struct iwl3945_priv *priv, struct iwl3945_rx_mem_buffer *rxb) { @@ -3917,6 +4016,7 @@ int iwl3945_rx_queue_update_write_ptr(struct iwl3945_priv *priv, struct iwl3945_ if (q->need_update == 0) goto exit_unlock; + /* If power-saving is in use, make sure device is awake */ if (test_bit(STATUS_POWER_PMI, &priv->status)) { reg = iwl3945_read32(priv, CSR_UCODE_DRV_GP1); @@ -3930,10 +4030,14 @@ int iwl3945_rx_queue_update_write_ptr(struct iwl3945_priv *priv, struct iwl3945_ if (rc) goto exit_unlock; + /* Device expects a multiple of 8 */ iwl3945_write_direct32(priv, FH_RSCSR_CHNL0_WPTR, q->write & ~0x7); iwl3945_release_nic_access(priv); + + /* Else device is assumed to be awake */ } else + /* Device expects a multiple of 8 */ iwl3945_write32(priv, FH_RSCSR_CHNL0_WPTR, q->write & ~0x7); @@ -3975,9 +4079,12 @@ static int iwl3945_rx_queue_restock(struct iwl3945_priv *priv) spin_lock_irqsave(&rxq->lock, flags); write = rxq->write & ~0x7; while ((iwl3945_rx_queue_space(rxq) > 0) && (rxq->free_count)) { + /* Get next free Rx buffer, remove from free list */ element = rxq->rx_free.next; rxb = list_entry(element, struct iwl3945_rx_mem_buffer, list); list_del(element); + + /* Point to Rx buffer via next RBD in circular buffer */ rxq->bd[rxq->write] = iwl3945_dma_addr2rbd_ptr(priv, rxb->dma_addr); rxq->queue[rxq->write] = rxb; rxq->write = (rxq->write + 1) & RX_QUEUE_MASK; @@ -3990,7 +4097,8 @@ static int iwl3945_rx_queue_restock(struct iwl3945_priv *priv) queue_work(priv->workqueue, &priv->rx_replenish); - /* If we've added more space for the firmware to place data, tell it */ + /* If we've added more space for the firmware to place data, tell it. + * Increment device's write pointer in multiples of 8. */ if ((write != (rxq->write & ~0x7)) || (abs(rxq->write - rxq->read) > 7)) { spin_lock_irqsave(&rxq->lock, flags); @@ -4023,6 +4131,8 @@ void iwl3945_rx_replenish(void *data) while (!list_empty(&rxq->rx_used)) { element = rxq->rx_used.next; rxb = list_entry(element, struct iwl3945_rx_mem_buffer, list); + + /* Alloc a new receive buffer */ rxb->skb = alloc_skb(IWL_RX_BUF_SIZE, __GFP_NOWARN | GFP_ATOMIC); if (!rxb->skb) { @@ -4036,6 +4146,8 @@ void iwl3945_rx_replenish(void *data) } priv->alloc_rxb_skb++; list_del(element); + + /* Get physical address of RB/SKB */ rxb->dma_addr = pci_map_single(priv->pci_dev, rxb->skb->data, IWL_RX_BUF_SIZE, PCI_DMA_FROMDEVICE); @@ -4080,12 +4192,16 @@ int iwl3945_rx_queue_alloc(struct iwl3945_priv *priv) spin_lock_init(&rxq->lock); INIT_LIST_HEAD(&rxq->rx_free); INIT_LIST_HEAD(&rxq->rx_used); + + /* Alloc the circular buffer of Read Buffer Descriptors (RBDs) */ rxq->bd = pci_alloc_consistent(dev, 4 * RX_QUEUE_SIZE, &rxq->dma_addr); if (!rxq->bd) return -ENOMEM; + /* Fill the rx_used queue with _all_ of the Rx buffers */ for (i = 0; i < RX_FREE_BUFFERS + RX_QUEUE_SIZE; i++) list_add_tail(&rxq->pool[i].list, &rxq->rx_used); + /* Set us so that we have processed and used all buffers, but have * not restocked the Rx queue with fresh buffers */ rxq->read = rxq->write = 0; @@ -4217,6 +4333,8 @@ static void iwl3945_rx_handle(struct iwl3945_priv *priv) int reclaim; unsigned long flags; + /* uCode's read index (stored in shared DRAM) indicates the last Rx + * buffer that the driver may process (last buffer filled by ucode). */ r = iwl3945_hw_get_rx_read(priv); i = rxq->read; @@ -4297,6 +4415,9 @@ static void iwl3945_rx_handle(struct iwl3945_priv *priv) iwl3945_rx_queue_restock(priv); } +/** + * iwl3945_tx_queue_update_write_ptr - Send new write index to hardware + */ static int iwl3945_tx_queue_update_write_ptr(struct iwl3945_priv *priv, struct iwl3945_tx_queue *txq) { @@ -4926,6 +5047,11 @@ static void iwl3945_init_band_reference(const struct iwl3945_priv *priv, int ban } } +/** + * iwl3945_get_channel_info - Find driver's private channel info + * + * Based on band and channel number. + */ const struct iwl3945_channel_info *iwl3945_get_channel_info(const struct iwl3945_priv *priv, int phymode, u16 channel) { @@ -4953,6 +5079,9 @@ const struct iwl3945_channel_info *iwl3945_get_channel_info(const struct iwl3945 #define CHECK_AND_PRINT(x) ((eeprom_ch_info[ch].flags & EEPROM_CHANNEL_##x) \ ? # x " " : "") +/** + * iwl3945_init_channel_map - Set up driver's info for all possible channels + */ static int iwl3945_init_channel_map(struct iwl3945_priv *priv) { int eeprom_ch_count = 0; @@ -5062,6 +5191,7 @@ static int iwl3945_init_channel_map(struct iwl3945_priv *priv) } } + /* Set up txpower settings in driver for all channels */ if (iwl3945_txpower_set_from_eeprom(priv)) return -EIO; @@ -8289,6 +8419,8 @@ static int iwl3945_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e struct ieee80211_hw *hw; int i; + /* Disabling hardware scan means that mac80211 will perform scans + * "the hard way", rather than using device's scan. */ if (iwl3945_param_disable_hw_scan) { IWL_DEBUG_INFO("Disabling hw_scan\n"); iwl3945_hw_ops.hw_scan = NULL; @@ -8319,6 +8451,8 @@ static int iwl3945_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e priv->hw = hw; priv->pci_dev = pdev; + + /* Select antenna (may be helpful if only one antenna is connected) */ priv->antenna = (enum iwl3945_antenna)iwl3945_param_antenna; #ifdef CONFIG_IWL3945_DEBUG iwl3945_debug_level = iwl3945_param_debug; @@ -8340,6 +8474,7 @@ static int iwl3945_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e /* Tell mac80211 our Tx characteristics */ hw->flags = IEEE80211_HW_HOST_GEN_BEACON_TEMPLATE; + /* 4 EDCA QOS priorities */ hw->queues = 4; spin_lock_init(&priv->lock); @@ -8360,6 +8495,7 @@ static int iwl3945_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e pci_set_master(pdev); + /* Clear the driver's (not device's) station table */ iwl3945_clear_stations_table(priv); priv->data_retry_limit = -1; @@ -8379,9 +8515,11 @@ static int iwl3945_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e err = pci_request_regions(pdev, DRV_NAME); if (err) goto out_pci_disable_device; + /* We disable the RETRY_TIMEOUT register (0x41) to keep * PCI Tx retries from interfering with C3 CPU state */ pci_write_config_byte(pdev, 0x41, 0x00); + priv->hw_base = pci_iomap(pdev, 0, 0); if (!priv->hw_base) { err = -ENODEV; @@ -8394,6 +8532,7 @@ static int iwl3945_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e /* Initialize module parameter values here */ + /* Disable radio (SW RF KILL) via parameter when loading driver */ if (iwl3945_param_disable) { set_bit(STATUS_RF_KILL_SW, &priv->status); IWL_DEBUG_INFO("Radio disabled.\n"); diff --git a/drivers/net/wireless/iwlwifi/iwl4965-base.c b/drivers/net/wireless/iwlwifi/iwl4965-base.c index 66aa938e316..43ce645e4a6 100644 --- a/drivers/net/wireless/iwlwifi/iwl4965-base.c +++ b/drivers/net/wireless/iwlwifi/iwl4965-base.c @@ -63,13 +63,13 @@ static int iwl4965_tx_queue_update_write_ptr(struct iwl4965_priv *priv, ******************************************************************************/ /* module parameters */ -static int iwl4965_param_disable_hw_scan; -static int iwl4965_param_debug; +static int iwl4965_param_disable_hw_scan; /* def: 0 = use 4965's h/w scan */ +static int iwl4965_param_debug; /* def: 0 = minimal debug log messages */ static int iwl4965_param_disable; /* def: enable radio */ static int iwl4965_param_antenna; /* def: 0 = both antennas (use diversity) */ int iwl4965_param_hwcrypto; /* def: using software encryption */ -static int iwl4965_param_qos_enable = 1; -int iwl4965_param_queues_num = IWL_MAX_NUM_QUEUES; +static int iwl4965_param_qos_enable = 1; /* def: 1 = use quality of service */ +int iwl4965_param_queues_num = IWL_MAX_NUM_QUEUES; /* def: 16 Tx queues */ /* * module name, copyright, version, etc. @@ -183,17 +183,24 @@ static void iwl4965_print_hex_dump(int level, void *p, u32 len) * * Theory of operation * - * A queue is a circular buffers with 'Read' and 'Write' pointers. - * 2 empty entries always kept in the buffer to protect from overflow. + * A Tx or Rx queue resides in host DRAM, and is comprised of a circular buffer + * of buffer descriptors, each of which points to one or more data buffers for + * the device to read from or fill. Driver and device exchange status of each + * queue via "read" and "write" pointers. Driver keeps minimum of 2 empty + * entries in each circular buffer, to protect against confusing empty and full + * queue states. + * + * The device reads or writes the data in the queues via the device's several + * DMA/FIFO channels. Each queue is mapped to a single DMA channel. * * For Tx queue, there are low mark and high mark limits. If, after queuing * the packet for Tx, free space become < low mark, Tx queue stopped. When * reclaiming packets (on 'tx done IRQ), if free space become > high mark, * Tx queue resumed. * - * The IWL operates with six queues, one receive queue in the device's - * sram, one transmit queue for sending commands to the device firmware, - * and four transmit queues for data. + * The 4965 operates with up to 17 queues: One receive queue, one transmit + * queue (#4) for sending commands to the device firmware, and 15 other + * Tx queues that may be mapped to prioritized Tx DMA/FIFO channels. ***************************************************/ static int iwl4965_queue_space(const struct iwl4965_queue *q) @@ -212,13 +219,21 @@ static int iwl4965_queue_space(const struct iwl4965_queue *q) return s; } -/* XXX: n_bd must be power-of-two size */ +/** + * iwl4965_queue_inc_wrap - increment queue index, wrap back to beginning + * @index -- current index + * @n_bd -- total number of entries in queue (must be power of 2) + */ static inline int iwl4965_queue_inc_wrap(int index, int n_bd) { return ++index & (n_bd - 1); } -/* XXX: n_bd must be power-of-two size */ +/** + * iwl4965_queue_dec_wrap - decrement queue index, wrap back to end + * @index -- current index + * @n_bd -- total number of entries in queue (must be power of 2) + */ static inline int iwl4965_queue_dec_wrap(int index, int n_bd) { return --index & (n_bd - 1); @@ -233,12 +248,17 @@ static inline int x2_queue_used(const struct iwl4965_queue *q, int i) static inline u8 get_cmd_index(struct iwl4965_queue *q, u32 index, int is_huge) { + /* This is for scan command, the big buffer at end of command array */ if (is_huge) - return q->n_window; + return q->n_window; /* must be power of 2 */ + /* Otherwise, use normal size buffers */ return index & (q->n_window - 1); } +/** + * iwl4965_queue_init - Initialize queue's high/low-water and read/write indexes + */ static int iwl4965_queue_init(struct iwl4965_priv *priv, struct iwl4965_queue *q, int count, int slots_num, u32 id) { @@ -267,11 +287,16 @@ static int iwl4965_queue_init(struct iwl4965_priv *priv, struct iwl4965_queue *q return 0; } +/** + * iwl4965_tx_queue_alloc - Alloc driver data and TFD CB for one Tx/cmd queue + */ static int iwl4965_tx_queue_alloc(struct iwl4965_priv *priv, struct iwl4965_tx_queue *txq, u32 id) { struct pci_dev *dev = priv->pci_dev; + /* Driver private data, only for Tx (not command) queues, + * not shared with device. */ if (id != IWL_CMD_QUEUE_NUM) { txq->txb = kmalloc(sizeof(txq->txb[0]) * TFD_QUEUE_SIZE_MAX, GFP_KERNEL); @@ -283,6 +308,8 @@ static int iwl4965_tx_queue_alloc(struct iwl4965_priv *priv, } else txq->txb = NULL; + /* Circular buffer of transmit frame descriptors (TFDs), + * shared with device */ txq->bd = pci_alloc_consistent(dev, sizeof(txq->bd[0]) * TFD_QUEUE_SIZE_MAX, &txq->q.dma_addr); @@ -320,7 +347,7 @@ int iwl4965_tx_queue_init(struct iwl4965_priv *priv, * For the command queue (#4), allocate command space + one big * command for scan, since scan command is very huge; the system will * not have two scans at the same time, so only one is needed. - * For normal Tx queues (all other queues), no super-size command + * For data Tx queues (all other queues), no super-size command * space is needed. */ len = sizeof(struct iwl4965_cmd) * slots_num; @@ -357,8 +384,8 @@ int iwl4965_tx_queue_init(struct iwl4965_priv *priv, * @txq: Transmit queue to deallocate. * * Empty queue by removing and destroying all BD's. - * Free all buffers. txq itself is not freed. - * + * Free all buffers. + * 0-fill, but do not free "txq" descriptor structure. */ void iwl4965_tx_queue_free(struct iwl4965_priv *priv, struct iwl4965_tx_queue *txq) { @@ -378,19 +405,21 @@ void iwl4965_tx_queue_free(struct iwl4965_priv *priv, struct iwl4965_tx_queue *t if (q->id == IWL_CMD_QUEUE_NUM) len += IWL_MAX_SCAN_SIZE; + /* De-alloc array of command/tx buffers */ pci_free_consistent(dev, len, txq->cmd, txq->dma_addr_cmd); - /* free buffers belonging to queue itself */ + /* De-alloc circular buffer of TFDs */ if (txq->q.n_bd) pci_free_consistent(dev, sizeof(struct iwl4965_tfd_frame) * txq->q.n_bd, txq->bd, txq->q.dma_addr); + /* De-alloc array of per-TFD driver data */ if (txq->txb) { kfree(txq->txb); txq->txb = NULL; } - /* 0 fill whole structure */ + /* 0-fill queue descriptor structure */ memset(txq, 0, sizeof(*txq)); } @@ -404,6 +433,11 @@ const u8 iwl4965_broadcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF /**************************************************************/ #if 0 /* temporary disable till we add real remove station */ +/** + * iwl4965_remove_station - Remove driver's knowledge of station. + * + * NOTE: This does not remove station from device's station table. + */ static u8 iwl4965_remove_station(struct iwl4965_priv *priv, const u8 *addr, int is_ap) { int index = IWL_INVALID_STATION; @@ -441,6 +475,11 @@ out: } #endif +/** + * iwl4965_clear_stations_table - Clear the driver's station table + * + * NOTE: This does not clear or otherwise alter the device's station table. + */ static void iwl4965_clear_stations_table(struct iwl4965_priv *priv) { unsigned long flags; @@ -453,6 +492,9 @@ static void iwl4965_clear_stations_table(struct iwl4965_priv *priv) spin_unlock_irqrestore(&priv->sta_lock, flags); } +/** + * iwl4965_add_station_flags - Add station to tables in driver and device + */ u8 iwl4965_add_station_flags(struct iwl4965_priv *priv, const u8 *addr, int is_ap, u8 flags) { int i; @@ -499,6 +541,7 @@ u8 iwl4965_add_station_flags(struct iwl4965_priv *priv, const u8 *addr, int is_a station->used = 1; priv->num_stations++; + /* Set up the REPLY_ADD_STA command to send to device */ memset(&station->sta, 0, sizeof(struct iwl4965_addsta_cmd)); memcpy(station->sta.sta.addr, addr, ETH_ALEN); station->sta.mode = 0; @@ -513,6 +556,8 @@ u8 iwl4965_add_station_flags(struct iwl4965_priv *priv, const u8 *addr, int is_a #endif /*CONFIG_IWL4965_HT*/ spin_unlock_irqrestore(&priv->sta_lock, flags_spin); + + /* Add station to device's station table */ iwl4965_send_add_station(priv, &station->sta, flags); return index; @@ -682,7 +727,11 @@ static int iwl4965_enqueue_hcmd(struct iwl4965_priv *priv, struct iwl4965_host_c fix_size, q->write_ptr, idx, IWL_CMD_QUEUE_NUM); txq->need_update = 1; + + /* Set up entry in queue's byte count circular buffer */ ret = iwl4965_tx_queue_update_wr_ptr(priv, txq, 0); + + /* Increment and update queue's write index */ q->write_ptr = iwl4965_queue_inc_wrap(q->write_ptr, q->n_bd); iwl4965_tx_queue_update_write_ptr(priv, txq); @@ -848,7 +897,10 @@ static int iwl4965_rxon_add_station(struct iwl4965_priv *priv, { u8 sta_id; + /* Add station to device's station table */ sta_id = iwl4965_add_station_flags(priv, addr, is_ap, 0); + + /* Set up default rate scaling table in device's station table */ iwl4965_add_station(priv, addr, is_ap); return sta_id; @@ -1574,7 +1626,7 @@ static void get_eeprom_mac(struct iwl4965_priv *priv, u8 *mac) /** * iwl4965_eeprom_init - read EEPROM contents * - * Load the EEPROM from adapter into priv->eeprom + * Load the EEPROM contents from adapter into priv->eeprom * * NOTE: This routine uses the non-debug IO access functions. */ @@ -1599,6 +1651,7 @@ int iwl4965_eeprom_init(struct iwl4965_priv *priv) return -ENOENT; } + /* Make sure driver (instead of uCode) is allowed to read EEPROM */ rc = iwl4965_eeprom_acquire_semaphore(priv); if (rc < 0) { IWL_ERROR("Failed to acquire EEPROM semaphore.\n"); @@ -2739,6 +2792,11 @@ static void iwl4965_build_tx_cmd_basic(struct iwl4965_priv *priv, cmd->cmd.tx.next_frame_len = 0; } +/** + * iwl4965_get_sta_id - Find station's index within station table + * + * If new IBSS station, create new entry in station table + */ static int iwl4965_get_sta_id(struct iwl4965_priv *priv, struct ieee80211_hdr *hdr) { @@ -2746,16 +2804,15 @@ static int iwl4965_get_sta_id(struct iwl4965_priv *priv, u16 fc = le16_to_cpu(hdr->frame_control); DECLARE_MAC_BUF(mac); - /* If this frame is broadcast or not data then use the broadcast - * station id */ + /* If this frame is broadcast or management, use broadcast station id */ if (((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA) || is_multicast_ether_addr(hdr->addr1)) return priv->hw_setting.bcast_sta_id; switch (priv->iw_mode) { - /* If this frame is part of a BSS network (we're a station), then - * we use the AP's station id */ + /* If we are a client station in a BSS network, use the special + * AP station entry (that's the only station we communicate with) */ case IEEE80211_IF_TYPE_STA: return IWL_AP_ID; @@ -2766,13 +2823,14 @@ static int iwl4965_get_sta_id(struct iwl4965_priv *priv, return sta_id; return priv->hw_setting.bcast_sta_id; - /* If this frame is part of a IBSS network, then we use the - * target specific station id */ + /* If this frame is going out to an IBSS network, find the station, + * or create a new station table entry */ case IEEE80211_IF_TYPE_IBSS: sta_id = iwl4965_hw_find_station(priv, hdr->addr1); if (sta_id != IWL_INVALID_STATION) return sta_id; + /* Create new station table entry */ sta_id = iwl4965_add_station_flags(priv, hdr->addr1, 0, CMD_ASYNC); if (sta_id != IWL_INVALID_STATION) @@ -2854,6 +2912,8 @@ static int iwl4965_tx_skb(struct iwl4965_priv *priv, spin_unlock_irqrestore(&priv->lock, flags); hdr_len = ieee80211_get_hdrlen(fc); + + /* Find (or create) index into station table for destination station */ sta_id = iwl4965_get_sta_id(priv, hdr); if (sta_id == IWL_INVALID_STATION) { DECLARE_MAC_BUF(mac); @@ -2882,30 +2942,52 @@ static int iwl4965_tx_skb(struct iwl4965_priv *priv, #endif /* CONFIG_IWL4965_HT_AGG */ #endif /* CONFIG_IWL4965_HT */ } + + /* Descriptor for chosen Tx queue */ txq = &priv->txq[txq_id]; q = &txq->q; spin_lock_irqsave(&priv->lock, flags); + /* Set up first empty TFD within this queue's circular TFD buffer */ tfd = &txq->bd[q->write_ptr]; memset(tfd, 0, sizeof(*tfd)); control_flags = (u32 *) tfd; idx = get_cmd_index(q, q->write_ptr, 0); + /* Set up driver data for this TFD */ memset(&(txq->txb[q->write_ptr]), 0, sizeof(struct iwl4965_tx_info)); txq->txb[q->write_ptr].skb[0] = skb; memcpy(&(txq->txb[q->write_ptr].status.control), ctl, sizeof(struct ieee80211_tx_control)); + + /* Set up first empty entry in queue's array of Tx/cmd buffers */ out_cmd = &txq->cmd[idx]; memset(&out_cmd->hdr, 0, sizeof(out_cmd->hdr)); memset(&out_cmd->cmd.tx, 0, sizeof(out_cmd->cmd.tx)); + + /* + * Set up the Tx-command (not MAC!) header. + * Store the chosen Tx queue and TFD index within the sequence field; + * after Tx, uCode's Tx response will return this value so driver can + * locate the frame within the tx queue and do post-tx processing. + */ out_cmd->hdr.cmd = REPLY_TX; out_cmd->hdr.sequence = cpu_to_le16((u16)(QUEUE_TO_SEQ(txq_id) | INDEX_TO_SEQ(q->write_ptr))); - /* copy frags header */ + + /* Copy MAC header from skb into command buffer */ memcpy(out_cmd->cmd.tx.hdr, hdr, hdr_len); - /* hdr = (struct ieee80211_hdr *)out_cmd->cmd.tx.hdr; */ + /* + * Use the first empty entry in this queue's command buffer array + * to contain the Tx command and MAC header concatenated together + * (payload data will be in another buffer). + * Size of this varies, due to varying MAC header length. + * If end is not dword aligned, we'll have 2 extra bytes at the end + * of the MAC header (device reads on dword boundaries). + * We'll tell device about this padding later. + */ len = priv->hw_setting.tx_cmd_len + sizeof(struct iwl4965_cmd_header) + hdr_len; @@ -2917,15 +2999,20 @@ static int iwl4965_tx_skb(struct iwl4965_priv *priv, else len_org = 0; + /* Physical address of this Tx command's header (not MAC header!), + * within command buffer array. */ txcmd_phys = txq->dma_addr_cmd + sizeof(struct iwl4965_cmd) * idx + offsetof(struct iwl4965_cmd, hdr); + /* Add buffer containing Tx command and MAC(!) header to TFD's + * first entry */ iwl4965_hw_txq_attach_buf_to_tfd(priv, tfd, txcmd_phys, len); if (!(ctl->flags & IEEE80211_TXCTL_DO_NOT_ENCRYPT)) iwl4965_build_tx_cmd_hwcrypto(priv, ctl, out_cmd, skb, 0); - /* 802.11 null functions have no payload... */ + /* Set up TFD's 2nd entry to point directly to remainder of skb, + * if any (802.11 null frames have no payload). */ len = skb->len - hdr_len; if (len) { phys_addr = pci_map_single(priv->pci_dev, skb->data + hdr_len, @@ -2933,9 +3020,11 @@ static int iwl4965_tx_skb(struct iwl4965_priv *priv, iwl4965_hw_txq_attach_buf_to_tfd(priv, tfd, phys_addr, len); } + /* Tell 4965 about any 2-byte padding after MAC header */ if (len_org) out_cmd->cmd.tx.tx_flags |= TX_CMD_FLG_MH_PAD_MSK; + /* Total # bytes to be transmitted */ len = (u16)skb->len; out_cmd->cmd.tx.len = cpu_to_le16(len); @@ -2965,8 +3054,10 @@ static int iwl4965_tx_skb(struct iwl4965_priv *priv, iwl4965_print_hex_dump(IWL_DL_TX, (u8 *)out_cmd->cmd.tx.hdr, ieee80211_get_hdrlen(fc)); + /* Set up entry for this TFD in Tx byte-count array */ iwl4965_tx_queue_update_wr_ptr(priv, txq, len); + /* Tell device the write index *just past* this latest filled TFD */ q->write_ptr = iwl4965_queue_inc_wrap(q->write_ptr, q->n_bd); rc = iwl4965_tx_queue_update_write_ptr(priv, txq); spin_unlock_irqrestore(&priv->lock, flags); @@ -3443,11 +3534,11 @@ static void iwl4965_txstatus_to_ieee(struct iwl4965_priv *priv, } /** - * iwl4965_tx_queue_reclaim - Reclaim Tx queue entries no more used by NIC. + * iwl4965_tx_queue_reclaim - Reclaim Tx queue entries already Tx'd * - * When FW advances 'R' index, all entries between old and - * new 'R' index need to be reclaimed. As result, some free space - * forms. If there is enough free space (> low mark), wake Tx queue. + * When FW advances 'R' index, all entries between old and new 'R' index + * need to be reclaimed. As result, some free space forms. If there is + * enough free space (> low mark), wake the stack that feeds us. */ int iwl4965_tx_queue_reclaim(struct iwl4965_priv *priv, int txq_id, int index) { @@ -3528,6 +3619,10 @@ static inline u32 iwl4965_get_scd_ssn(struct iwl4965_tx_resp *tx_resp) return le32_to_cpu(*scd_ssn) & MAX_SN; } + +/** + * iwl4965_tx_status_reply_tx - Handle Tx rspnse for frames in aggregation queue + */ static int iwl4965_tx_status_reply_tx(struct iwl4965_priv *priv, struct iwl4965_ht_agg *agg, struct iwl4965_tx_resp *tx_resp, @@ -3542,14 +3637,16 @@ static int iwl4965_tx_status_reply_tx(struct iwl4965_priv *priv, u16 seq; if (agg->wait_for_ba) - IWL_DEBUG_TX_REPLY("got tx repsons w/o back\n"); + IWL_DEBUG_TX_REPLY("got tx response w/o block-ack\n"); agg->frame_count = tx_resp->frame_count; agg->start_idx = start_idx; agg->rate_n_flags = le32_to_cpu(tx_resp->rate_n_flags); agg->bitmap0 = agg->bitmap1 = 0; + /* # frames attempted by Tx command */ if (agg->frame_count == 1) { + /* Only one frame was attempted; no block-ack will arrive */ struct iwl4965_tx_queue *txq ; status = le32_to_cpu(frame_status[0]); @@ -3578,9 +3675,11 @@ static int iwl4965_tx_status_reply_tx(struct iwl4965_priv *priv, agg->wait_for_ba = 0; } else { + /* Two or more frames were attempted; expect block-ack */ u64 bitmap = 0; int start = agg->start_idx; + /* Construct bit-map of pending frames within Tx window */ for (i = 0; i < agg->frame_count; i++) { u16 sc; status = le32_to_cpu(frame_status[i]); @@ -3644,6 +3743,9 @@ static int iwl4965_tx_status_reply_tx(struct iwl4965_priv *priv, #endif #endif +/** + * iwl4965_rx_reply_tx - Handle standard (non-aggregation) Tx response + */ static void iwl4965_rx_reply_tx(struct iwl4965_priv *priv, struct iwl4965_rx_mem_buffer *rxb) { @@ -4265,6 +4367,7 @@ int iwl4965_rx_queue_update_write_ptr(struct iwl4965_priv *priv, struct iwl4965_ if (q->need_update == 0) goto exit_unlock; + /* If power-saving is in use, make sure device is awake */ if (test_bit(STATUS_POWER_PMI, &priv->status)) { reg = iwl4965_read32(priv, CSR_UCODE_DRV_GP1); @@ -4278,10 +4381,14 @@ int iwl4965_rx_queue_update_write_ptr(struct iwl4965_priv *priv, struct iwl4965_ if (rc) goto exit_unlock; + /* Device expects a multiple of 8 */ iwl4965_write_direct32(priv, FH_RSCSR_CHNL0_WPTR, q->write & ~0x7); iwl4965_release_nic_access(priv); + + /* Else device is assumed to be awake */ } else + /* Device expects a multiple of 8 */ iwl4965_write32(priv, FH_RSCSR_CHNL0_WPTR, q->write & ~0x7); @@ -4324,9 +4431,12 @@ static int iwl4965_rx_queue_restock(struct iwl4965_priv *priv) spin_lock_irqsave(&rxq->lock, flags); write = rxq->write & ~0x7; while ((iwl4965_rx_queue_space(rxq) > 0) && (rxq->free_count)) { + /* Get next free Rx buffer, remove from free list */ element = rxq->rx_free.next; rxb = list_entry(element, struct iwl4965_rx_mem_buffer, list); list_del(element); + + /* Point to Rx buffer via next RBD in circular buffer */ rxq->bd[rxq->write] = iwl4965_dma_addr2rbd_ptr(priv, rxb->dma_addr); rxq->queue[rxq->write] = rxb; rxq->write = (rxq->write + 1) & RX_QUEUE_MASK; @@ -4339,7 +4449,8 @@ static int iwl4965_rx_queue_restock(struct iwl4965_priv *priv) queue_work(priv->workqueue, &priv->rx_replenish); - /* If we've added more space for the firmware to place data, tell it */ + /* If we've added more space for the firmware to place data, tell it. + * Increment device's write pointer in multiples of 8. */ if ((write != (rxq->write & ~0x7)) || (abs(rxq->write - rxq->read) > 7)) { spin_lock_irqsave(&rxq->lock, flags); @@ -4372,6 +4483,8 @@ void iwl4965_rx_replenish(void *data) while (!list_empty(&rxq->rx_used)) { element = rxq->rx_used.next; rxb = list_entry(element, struct iwl4965_rx_mem_buffer, list); + + /* Alloc a new receive buffer */ rxb->skb = alloc_skb(IWL_RX_BUF_SIZE, __GFP_NOWARN | GFP_ATOMIC); if (!rxb->skb) { @@ -4385,6 +4498,8 @@ void iwl4965_rx_replenish(void *data) } priv->alloc_rxb_skb++; list_del(element); + + /* Get physical address of RB/SKB */ rxb->dma_addr = pci_map_single(priv->pci_dev, rxb->skb->data, IWL_RX_BUF_SIZE, PCI_DMA_FROMDEVICE); @@ -4429,12 +4544,16 @@ int iwl4965_rx_queue_alloc(struct iwl4965_priv *priv) spin_lock_init(&rxq->lock); INIT_LIST_HEAD(&rxq->rx_free); INIT_LIST_HEAD(&rxq->rx_used); + + /* Alloc the circular buffer of Read Buffer Descriptors (RBDs) */ rxq->bd = pci_alloc_consistent(dev, 4 * RX_QUEUE_SIZE, &rxq->dma_addr); if (!rxq->bd) return -ENOMEM; + /* Fill the rx_used queue with _all_ of the Rx buffers */ for (i = 0; i < RX_FREE_BUFFERS + RX_QUEUE_SIZE; i++) list_add_tail(&rxq->pool[i].list, &rxq->rx_used); + /* Set us so that we have processed and used all buffers, but have * not restocked the Rx queue with fresh buffers */ rxq->read = rxq->write = 0; @@ -4566,6 +4685,8 @@ static void iwl4965_rx_handle(struct iwl4965_priv *priv) int reclaim; unsigned long flags; + /* uCode's read index (stored in shared DRAM) indicates the last Rx + * buffer that the driver may process (last buffer filled by ucode). */ r = iwl4965_hw_get_rx_read(priv); i = rxq->read; @@ -4649,6 +4770,9 @@ static void iwl4965_rx_handle(struct iwl4965_priv *priv) iwl4965_rx_queue_restock(priv); } +/** + * iwl4965_tx_queue_update_write_ptr - Send new write index to hardware + */ static int iwl4965_tx_queue_update_write_ptr(struct iwl4965_priv *priv, struct iwl4965_tx_queue *txq) { @@ -5282,6 +5406,11 @@ static void iwl4965_init_band_reference(const struct iwl4965_priv *priv, } } +/** + * iwl4965_get_channel_info - Find driver's private channel info + * + * Based on band and channel number. + */ const struct iwl4965_channel_info *iwl4965_get_channel_info(const struct iwl4965_priv *priv, int phymode, u16 channel) { @@ -5309,6 +5438,9 @@ const struct iwl4965_channel_info *iwl4965_get_channel_info(const struct iwl4965 #define CHECK_AND_PRINT(x) ((eeprom_ch_info[ch].flags & EEPROM_CHANNEL_##x) \ ? # x " " : "") +/** + * iwl4965_init_channel_map - Set up driver's info for all possible channels + */ static int iwl4965_init_channel_map(struct iwl4965_priv *priv) { int eeprom_ch_count = 0; @@ -5418,6 +5550,7 @@ static int iwl4965_init_channel_map(struct iwl4965_priv *priv) } } + /* Two additional EEPROM bands for 2.4 and 5 GHz FAT channels */ for (band = 6; band <= 7; band++) { int phymode; u8 fat_extension_chan; @@ -5425,7 +5558,9 @@ static int iwl4965_init_channel_map(struct iwl4965_priv *priv) iwl4965_init_band_reference(priv, band, &eeprom_ch_count, &eeprom_ch_info, &eeprom_ch_index); + /* EEPROM band 6 is 2.4, band 7 is 5 GHz */ phymode = (band == 6) ? MODE_IEEE80211B : MODE_IEEE80211A; + /* Loop through each band adding each of the channels */ for (ch = 0; ch < eeprom_ch_count; ch++) { @@ -5437,11 +5572,13 @@ static int iwl4965_init_channel_map(struct iwl4965_priv *priv) else fat_extension_chan = HT_IE_EXT_CHANNEL_ABOVE; + /* Set up driver's info for lower half */ iwl4965_set_fat_chan_info(priv, phymode, eeprom_ch_index[ch], &(eeprom_ch_info[ch]), fat_extension_chan); + /* Set up driver's info for upper half */ iwl4965_set_fat_chan_info(priv, phymode, (eeprom_ch_index[ch] + 4), &(eeprom_ch_info[ch]), @@ -8951,6 +9088,8 @@ static int iwl4965_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e struct ieee80211_hw *hw; int i; + /* Disabling hardware scan means that mac80211 will perform scans + * "the hard way", rather than using device's scan. */ if (iwl4965_param_disable_hw_scan) { IWL_DEBUG_INFO("Disabling hw_scan\n"); iwl4965_hw_ops.hw_scan = NULL; @@ -9002,9 +9141,11 @@ static int iwl4965_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e /* Tell mac80211 our Tx characteristics */ hw->flags = IEEE80211_HW_HOST_GEN_BEACON_TEMPLATE; + /* Default value; 4 EDCA QOS priorities */ hw->queues = 4; #ifdef CONFIG_IWL4965_HT #ifdef CONFIG_IWL4965_HT_AGG + /* Enhanced value; more queues, to support 11n aggregation */ hw->queues = 16; #endif /* CONFIG_IWL4965_HT_AGG */ #endif /* CONFIG_IWL4965_HT */ @@ -9028,6 +9169,7 @@ static int iwl4965_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e pci_set_master(pdev); + /* Clear the driver's (not device's) station table */ iwl4965_clear_stations_table(priv); priv->data_retry_limit = -1; @@ -9047,9 +9189,11 @@ static int iwl4965_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e err = pci_request_regions(pdev, DRV_NAME); if (err) goto out_pci_disable_device; + /* We disable the RETRY_TIMEOUT register (0x41) to keep * PCI Tx retries from interfering with C3 CPU state */ pci_write_config_byte(pdev, 0x41, 0x00); + priv->hw_base = pci_iomap(pdev, 0, 0); if (!priv->hw_base) { err = -ENODEV; @@ -9062,6 +9206,7 @@ static int iwl4965_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e /* Initialize module parameter values here */ + /* Disable radio (SW RF KILL) via parameter when loading driver */ if (iwl4965_param_disable) { set_bit(STATUS_RF_KILL_SW, &priv->status); IWL_DEBUG_INFO("Radio disabled.\n"); @@ -9076,6 +9221,7 @@ static int iwl4965_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e priv->valid_antenna = 0x7; /* assume all 3 connected */ priv->ps_mode = IWL_MIMO_PS_NONE; + /* Choose which receivers/antennas to use */ iwl4965_set_rxon_chain(priv); printk(KERN_INFO DRV_NAME |