From 7dc12e84eff7f934e2456a858ad23d3743c69578 Mon Sep 17 00:00:00 2001 From: Takashi Sakamoto Date: Mon, 8 Sep 2025 10:21:04 +0900 Subject: [PATCH] firewire: core: code refactoring to evaluate transaction result to CSR_BUS_MANAGER_ID The call of bm_work should be done after acquiring spin lock of fw_card. For asynchronous transaction, the lock should be released temporarily due to event waiting. A commit 27310d561622 ("firewire: core: use guard macro to maintain properties of fw_card") applied scoped_guard() to the bm_work function, however it looks hard to follow to the control flow. This commit refactors the spin lock acquisition after the transaction. Link: https://lore.kernel.org/r/20250908012108.514698-8-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto --- drivers/firewire/core-card.c | 30 ++++++++++++++++-------------- 1 file changed, 16 insertions(+), 14 deletions(-) diff --git a/drivers/firewire/core-card.c b/drivers/firewire/core-card.c index b98797e4f1d4b..e1a7a151b109d 100644 --- a/drivers/firewire/core-card.c +++ b/drivers/firewire/core-card.c @@ -291,7 +291,7 @@ static void bm_work(struct work_struct *work) struct fw_card *card __free(card_unref) = from_work(card, work, bm_work.work); struct fw_device *root_device, *irm_device; struct fw_node *root_node __free(node_unref) = NULL; - int root_id, new_root_id, irm_id, bm_id, local_id; + int root_id, new_root_id, irm_id, local_id; int gap_count, generation, grace; bool do_reset = false; bool root_device_is_running; @@ -376,19 +376,22 @@ static void bm_work(struct work_struct *work) if (rcode == RCODE_GENERATION) return; - bm_id = be32_to_cpu(data[0]); + spin_lock_irq(&card->lock); - scoped_guard(spinlock_irq, &card->lock) { - if (rcode == RCODE_COMPLETE && generation == card->generation) - card->bm_node_id = - bm_id == 0x3f ? local_id : 0xffc0 | bm_id; - } + if (rcode == RCODE_COMPLETE) { + int bm_id = be32_to_cpu(data[0]); - if (rcode == RCODE_COMPLETE && bm_id != 0x3f) { - /* Somebody else is BM. Only act as IRM. */ - if (local_id == irm_id) - allocate_broadcast_channel(card, generation); - return; + if (generation == card->generation) + card->bm_node_id = bm_id == 0x3f ? local_id : 0xffc0 | bm_id; + + if (bm_id != 0x3f) { + spin_unlock_irq(&card->lock); + + // Somebody else is BM. Only act as IRM. + if (local_id == irm_id) + allocate_broadcast_channel(card, generation); + return; + } } if (rcode == RCODE_SEND_ERROR) { @@ -397,12 +400,11 @@ static void bm_work(struct work_struct *work) * some local problem. Let's try again later and hope * that the problem has gone away by then. */ + spin_unlock_irq(&card->lock); fw_schedule_bm_work(card, DIV_ROUND_UP(HZ, 8)); return; } - spin_lock_irq(&card->lock); - if (rcode != RCODE_COMPLETE && !keep_this_irm) { /* * The lock request failed, maybe the IRM -- 2.47.3