From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shyam Iyer Subject: [PATCH] [net][bna] Separate handling of irq type flags variable from the irq_flags request_irq variable Date: Thu, 14 Jul 2011 21:00:32 -0400 Message-ID: <1310691632-22914-1-git-send-email-shyam_iyer@dell.com> Cc: rmody@brocade.com, ddutt@brocade.com, huangj@brocade.com, davem@davemloft.net, ivecera@redhat.com, Shyam Iyer To: netdev@vger.kernel.org Return-path: Received: from mail-qy0-f181.google.com ([209.85.216.181]:35896 "EHLO mail-qy0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753503Ab1GOBAn (ORCPT ); Thu, 14 Jul 2011 21:00:43 -0400 Received: by qyk9 with SMTP id 9so489106qyk.19 for ; Thu, 14 Jul 2011 18:00:42 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: Commit 5f77898de17ff983ff0e2988b73a6bdf4b6f9f8b 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 --- drivers/net/bna/bnad.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/bna/bnad.c b/drivers/net/bna/bnad.c index 44e219c..ea13605 100644 --- a/drivers/net/bna/bnad.c +++ b/drivers/net/bna/bnad.c @@ -1111,7 +1111,7 @@ 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; @@ -1125,6 +1125,7 @@ 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 { @@ -1135,7 +1136,6 @@ 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); /* @@ -1146,7 +1146,7 @@ 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) { -- 1.7.5.4