From 83db801ce8c644edee49f4364c7ebdfef1657762 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Kristian=20H=C3=B8gsberg?= Date: Fri, 26 Jan 2007 00:37:50 -0500 Subject: firewire: Implement gap count optimization. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Kristian Høgsberg Signed-off-by: Stefan Richter --- drivers/firewire/fw-card.c | 46 ++++++++++++++++++++++++++++++++-------------- 1 file changed, 32 insertions(+), 14 deletions(-) (limited to 'drivers/firewire/fw-card.c') diff --git a/drivers/firewire/fw-card.c b/drivers/firewire/fw-card.c index c8b7d695c81..307c8b85138 100644 --- a/drivers/firewire/fw-card.c +++ b/drivers/firewire/fw-card.c @@ -186,14 +186,17 @@ fw_core_remove_descriptor (struct fw_descriptor *desc) } EXPORT_SYMBOL(fw_core_remove_descriptor); +static const char gap_count_table[] = { + 63, 5, 7, 8, 10, 13, 16, 18, 21, 24, 26, 29, 32, 35, 37, 40 +}; + static void fw_card_irm_work(struct work_struct *work) { - struct fw_card *card = - container_of(work, struct fw_card, work.work); + struct fw_card *card = container_of(work, struct fw_card, work.work); struct fw_device *root; unsigned long flags; - int new_irm_id, generation; + int root_id, new_irm_id, gap_count, generation, do_reset = 0; /* FIXME: This simple bus management unconditionally picks a * cycle master if the current root can't do it. We need to @@ -206,35 +209,50 @@ fw_card_irm_work(struct work_struct *work) generation = card->generation; root = card->root_node->data; + root_id = card->root_node->node_id; - if (root == NULL) + if (root == NULL) { /* Either link_on is false, or we failed to read the * config rom. In either case, pick another root. */ new_irm_id = card->local_node->node_id; - else if (root->state != FW_DEVICE_RUNNING) + } else if (root->state != FW_DEVICE_RUNNING) { /* If we haven't probed this device yet, bail out now * and let's try again once that's done. */ - new_irm_id = -1; - else if (root->config_rom[2] & bib_cmc) + new_irm_id = root_id; + } else if (root->config_rom[2] & bib_cmc) { /* FIXME: I suppose we should set the cmstr bit in the * STATE_CLEAR register of this node, as described in * 1394-1995, 8.4.2.6. Also, send out a force root * packet for this node. */ - new_irm_id = -1; - else + new_irm_id = root_id; + } else { /* Current root has an active link layer and we * successfully read the config rom, but it's not * cycle master capable. */ new_irm_id = card->local_node->node_id; + } + + /* Now figure out what gap count to set. */ + if (card->topology_type == FW_TOPOLOGY_A && + card->root_node->max_hops < ARRAY_SIZE(gap_count_table)) + gap_count = gap_count_table[card->root_node->max_hops]; + else + gap_count = 63; + + /* Finally, figure out if we should do a reset or not. If we've + * done less that 5 resets with the same physical topology and we + * have either a new root or a new gap count setting, let's do it. */ - if (card->irm_retries++ > 5) - new_irm_id = -1; + if (card->irm_retries++ < 5 && + (card->gap_count != gap_count || new_irm_id != root_id)) + do_reset = 1; spin_unlock_irqrestore(&card->lock, flags); - if (new_irm_id > 0) { - fw_notify("Trying to become root (card %d)\n", card->index); - fw_send_force_root(card, new_irm_id, generation); + if (do_reset) { + fw_notify("phy config: card %d, new root=%x, gap_count=%d\n", + card->index, new_irm_id, gap_count); + fw_send_phy_config(card, new_irm_id, generation, gap_count); fw_core_initiate_bus_reset(card, 1); } } -- cgit v1.2.3