From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH] QStor SATA/RAID driver for 2.6.9-rc3 Date: Tue, 12 Oct 2004 13:42:19 -0400 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <416C177B.6030504@pobox.com> References: <4161A06D.8010601@rtr.ca> <416547B6.5080505@rtr.ca> <20041007150709.B12688@i nfradead.org> <4165624C.5060405@rtr.ca> <416565DB.4050006@pobox.com> <4165 A 4 5D.2090200@rtr.ca> <4165A766.1040104@pobox.com> <4165A85D.7080704@rtr.ca > <4 165AB1B.8000204@pobox.com> <4165ACF8.8060208@rtr.ca> <20041007221537. A17 712@infradead.org> <1097241583.2412.15.camel@mulgrave> <4166AF2F.607090 4@rtr.ca> <1097249266.1678.40.camel@mulgrave> <4166B48E.3020006@rtr.ca> <1097250465.2412.49.camel@mulgrave> <416C0D55.1020603@rtr.ca> <1097601478.2044.103.camel@mulgrave> <416C12CC.1050301@rtr.ca> <1097602220.2044.119.camel@mulgrave> <416C157A.6030400@rtr.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:64671 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id S267435AbUJLRmd (ORCPT ); Tue, 12 Oct 2004 13:42:33 -0400 In-Reply-To: <416C157A.6030400@rtr.ca> List-Id: linux-scsi@vger.kernel.org To: Mark Lord Cc: James Bottomley , Christoph Hellwig , Mark Lord , Linux Kernel , SCSI Mailing List Mark Lord wrote: > It's been there since day one. The interrupt handling sometimes requires > more functionality than is available at interrupt time, so it uses > schedule_work to have a bottom half re-run itself from thread context. > This is needed in the error-processing and hot plug paths. ewwww :) If you find yourself calling your irq path from non-irq-context code, back up, you're going down the wrong path. The usual way to do what you want is either 1) wrap all code that _might_ be called from inside interrupt handler inside spin_lock_irqsave() [except when you are in the interrupt handler, of course, which is merely spin_lock() Any code that checks "if (in_interrupt())" should be shot on sight :) 2) have both interrupt and non-interrupt contexts fire a tasklet using tasklet_schedule(). Your tasklet function then does the real work. Jeff