From 776caeb2f11d8e9f7ba825188537e4f07b4f91ed Mon Sep 17 00:00:00 2001 From: Shyam Iyer Date: Thu, 14 Jul 2011 15:00:32 +0000 Subject: [PATCH] Separate handling of irq type flags variable from the irq_flags request_irq variable Commit f065f6b32680d76eee9cb88a7d1fd9da9397e039 does not completely fix the problem of handling allocations with irqs disabled.. The below patch on top of it fixes the problem completely. Based on review by "Ivan Vecera" .. " Small note, the root of the problem was that non-atomic allocation was requested with IRQs disabled. Your patch description does not contain wwhy were the IRQs disabled. The function bnad_mbox_irq_alloc incorrectly uses 'flags' var for two different things, 1) to save current CPU flags and 2) for request_irq call. First the spin_lock_irqsave disables the IRQs and saves _all_ CPU flags (including one that enables/disables interrupts) to 'flags'. Then the 'flags' is overwritten by 0 or 0x80 (IRQF_SHARED). Finally the spin_unlock_irqrestore should restore saved flags, but these flags are now either 0x00 or 0x80. The interrupt bit value in flags register on x86 arch is 0x100. This means that the interrupt bit is zero (IRQs disabled) after spin_unlock_irqrestore so the request_irq function is called with disabled interrupts. " Signed-off-by: Shyam Iyer Signed-off-by: David S. Miller --- drivers/net/bna/bnad.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/bna/bnad.c b/drivers/net/bna/bnad.c index 795b93b73b125..fa997bfc2e53e 100644 --- a/drivers/net/bna/bnad.c +++ b/drivers/net/bna/bnad.c @@ -1109,7 +1109,7 @@ bnad_mbox_irq_alloc(struct bnad *bnad, struct bna_intr_info *intr_info) { int err = 0; - unsigned long irq_flags = 0, flags; + unsigned long irq_flags, flags; u32 irq; irq_handler_t irq_handler; @@ -1123,6 +1123,7 @@ bnad_mbox_irq_alloc(struct bnad *bnad, if (bnad->cfg_flags & BNAD_CF_MSIX) { irq_handler = (irq_handler_t)bnad_msix_mbox_handler; irq = bnad->msix_table[bnad->msix_num - 1].vector; + irq_flags = 0; intr_info->intr_type = BNA_INTR_T_MSIX; intr_info->idl[0].vector = bnad->msix_num - 1; } else { @@ -1133,7 +1134,6 @@ bnad_mbox_irq_alloc(struct bnad *bnad, /* intr_info->idl.vector = 0 ? */ } spin_unlock_irqrestore(&bnad->bna_lock, flags); - flags = irq_flags; sprintf(bnad->mbox_irq_name, "%s", BNAD_NAME); /* @@ -1144,7 +1144,7 @@ bnad_mbox_irq_alloc(struct bnad *bnad, BNAD_UPDATE_CTR(bnad, mbox_intr_disabled); - err = request_irq(irq, irq_handler, flags, + err = request_irq(irq, irq_handler, irq_flags, bnad->mbox_irq_name, bnad); if (err) { -- 2.39.5