diff options
| author | Ben Cahill <ben.m.cahill@intel.com> | 2007-11-29 11:10:03 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-01-28 15:05:28 -0800 |
| commit | aad141433b630e3e28bab1e27606a688b22dbcc1 (patch) | |
| tree | 461f8a983c3609c25551191558ca8ac7833c589d | |
| parent | 0c434c5a7f9983c8ee3c8943924db8c5fb1d12bd (diff) | |
iwlwifi: document keep-warm buffer
Document keep-warm buffer
Consolidate flow handler address definitions
Signed-off-by: Ben Cahill <ben.m.cahill@intel.com>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
| -rw-r--r-- | drivers/net/wireless/iwlwifi/iwl-4965-hw.h | 39 |
1 files changed, 28 insertions, 11 deletions
diff --git a/drivers/net/wireless/iwlwifi/iwl-4965-hw.h b/drivers/net/wireless/iwlwifi/iwl-4965-hw.h index 4a2fa80acff..8698bf77fd0 100644 --- a/drivers/net/wireless/iwlwifi/iwl-4965-hw.h +++ b/drivers/net/wireless/iwlwifi/iwl-4965-hw.h @@ -1282,20 +1282,37 @@ enum { /********************* END TXPOWER *****************************************/ +/****************************/ /* Flow Handler Definitions */ +/****************************/ -/**********************/ -/* Addresses */ -/**********************/ - +/* + * This I/O area is directly read/writable by driver (e.g. Linux uses writel()) + * Addresses are offsets from device's PCI hardware base address. + */ #define FH_MEM_LOWER_BOUND (0x1000) #define FH_MEM_UPPER_BOUND (0x1EF0) -#define IWL_FH_REGS_LOWER_BOUND (0x1000) -#define IWL_FH_REGS_UPPER_BOUND (0x2000) - +/** + * Keep-Warm (KW) buffer base address. + * + * Driver must allocate a 4KByte buffer that is used by 4965 for keeping the + * host DRAM powered on (via dummy accesses to DRAM) to maintain low-latency + * DRAM access when 4965 is Txing or Rxing. The dummy accesses prevent host + * from going into a power-savings mode that would cause higher DRAM latency, + * and possible data over/under-runs, before all Tx/Rx is complete. + * + * Driver loads IWL_FH_KW_MEM_ADDR_REG with the physical address (bits 35:4) + * of the buffer, which must be 4K aligned. Once this is set up, the 4965 + * automatically invokes keep-warm accesses when normal accesses might not + * be sufficient to maintain fast DRAM response. + * + * Bit fields: + * 31-0: Keep-warm buffer physical base address [35:4], must be 4K aligned + */ #define IWL_FH_KW_MEM_ADDR_REG (FH_MEM_LOWER_BOUND + 0x97C) + /* CBBC Area - Circular buffers base address cache pointers table */ #define FH_MEM_CBBC_LOWER_BOUND (FH_MEM_LOWER_BOUND + 0x9D0) #define FH_MEM_CBBC_UPPER_BOUND (FH_MEM_LOWER_BOUND + 0xA10) @@ -1326,16 +1343,16 @@ enum { #define FH_MEM_RSSR_RX_ENABLE_ERR_IRQ2DRV (FH_MEM_RSSR_LOWER_BOUND + 0x008) /* TCSR */ -#define IWL_FH_TCSR_LOWER_BOUND (IWL_FH_REGS_LOWER_BOUND + 0xD00) -#define IWL_FH_TCSR_UPPER_BOUND (IWL_FH_REGS_LOWER_BOUND + 0xE60) +#define IWL_FH_TCSR_LOWER_BOUND (FH_MEM_LOWER_BOUND + 0xD00) +#define IWL_FH_TCSR_UPPER_BOUND (FH_MEM_LOWER_BOUND + 0xE60) #define IWL_FH_TCSR_CHNL_TX_CONFIG_REG(_chnl) \ (IWL_FH_TCSR_LOWER_BOUND + 0x20 * _chnl) /* TSSR Area - Tx shared status registers */ /* TSSR */ -#define IWL_FH_TSSR_LOWER_BOUND (IWL_FH_REGS_LOWER_BOUND + 0xEA0) -#define IWL_FH_TSSR_UPPER_BOUND (IWL_FH_REGS_LOWER_BOUND + 0xEC0) +#define IWL_FH_TSSR_LOWER_BOUND (FH_MEM_LOWER_BOUND + 0xEA0) +#define IWL_FH_TSSR_UPPER_BOUND (FH_MEM_LOWER_BOUND + 0xEC0) #define IWL_FH_TSSR_TX_STATUS_REG (IWL_FH_TSSR_LOWER_BOUND + 0x010) |