From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH UPDATED #upstream-fixes,#upstream] sata_sil24: fix IRQ clearing race when PCIX_IRQ_WOC is used Date: Tue, 25 Sep 2007 21:39:18 -0400 Message-ID: <46F9B846.7000505@garzik.org> References: <20070923032614.GI10660@htj.dyndns.org> <20070923033705.GJ10660@htj.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:52579 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752690AbXIZBjU (ORCPT ); Tue, 25 Sep 2007 21:39:20 -0400 In-Reply-To: <20070923033705.GJ10660@htj.dyndns.org> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Tejun Heo Cc: linux-ide@vger.kernel.org Tejun Heo wrote: > When PCIX_IRQ_WOC is used, sil24 has an inherent race condition > between clearing IRQ pending and reading IRQ status. If IRQ pending > is cleared after reading IRQ status, there's possibility of lost IRQ. > If IRQ pending is cleared before reading IRQ status, spurious IRQs > will occur. > > sata_sil24 till now cleared IRQ pending after reading IRQ status thus > losing IRQs on machines where PCIX_IRQ_WOC was used. Reverse the > order and ignore spurious IRQs if PCIX_IRQ_WOC. > > Signed-off-by: Tejun Heo > --- > The previous patch contained a stupid mistake. This is the correct > one. > > drivers/ata/sata_sil24.c | 16 ++++++++++++---- > 1 file changed, 12 insertions(+), 4 deletions(-) applied