From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755069Ab2CHOPN (ORCPT ); Thu, 8 Mar 2012 09:15:13 -0500 Received: from sr-smtp.usish.com ([210.5.144.203]:49847 "EHLO sr-smtp.usish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752884Ab2CHOPL (ORCPT ); Thu, 8 Mar 2012 09:15:11 -0500 Date: Thu, 8 Mar 2012 22:15:03 +0800 From: jack_wang To: "Mark Salyzyn" , "santosh nayak" Cc: "Mark Salyzyn" , lindar_liu , "James Bottomley" , linux-scsi , linux-kernel , kernel-janitors , "Dan Carpenter" Reply-To: jack_wang Subject: Re: Re: [PATCH 1/2] [SCSI] pm8001: Fix bogus interrupt state flag issue. References: <1330263210-25134-1-git-send-email-santoshprasadnayak@gmail.com>, <528D7E8A-B2F6-4EDB-A7C0-E0BF494038D0@xyratex.com> X-Priority: 3 X-Has-Attach: no X-Mailer: Foxmail 7.0.1.87[cn] Mime-Version: 1.0 Message-ID: <201203082215017182231@usish.com> Content-Type: text/plain; charset="gb2312" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by nfs id q28EG3SU023456 Thanks Mark for look into this.You're right. The change for task_state_lock is not right. Sorry for not look carefully about the change. -------------- jack_wang >NAK > >In the fragment below, the 'spin_lock_irqsave(&t->task_state_lock, flags);' is 100% legitimate. The change you did was not inert, and result in the IRQ being disabled upon exit should a SAS_TASK_STATE_ABORTED task state condition occur. > >I propose (annotated below) you leave the flags automatic variable, but uninitialized. The changes surrounding spin_*lock_irq*(&pm8001_ha->lock, flags) are OK, but revert back the changes surrounding the spin_*lock_irq*(&t->task->state_lock,flags) so that lock would be properly nested. > >To be pedantic, and to be more correct, this code should have spawned a work queue task to perform the t->task_done(t) operation in a separate thread rather than inline and precariously unlocked; but that would be beyond the scope of these changes and should be left for future work to decide if it is even necessary. Not sure how such a change would affect performance (using the work queue) ... so I am 'afraid' of pushing such a change in any case given the relatively reliable operation of this driver (and the dynamic nature of the changes Dan is making to the SATA side of things for instance ;-} ). > >I am sorry for taking so long to get to the task of reviewing this (and the previous) code. I look forward to your comments. > >Sincerely -- Mark Salyzyn > >On Feb 26, 2012, at 8:33 AM, santosh nayak wrote: > >> @@ -2207,7 +2206,6 @@ mpi_sata_completion(struct pm8001_hba_info *pm8001_ha, void *piomb) >> static void mpi_sata_event(struct pm8001_hba_info *pm8001_ha , void *piomb) >> { >> struct sas_task *t; >> - unsigned long flags = 0; >MGS> unsigned long flags; >> struct task_status_struct *ts; >> struct pm8001_ccb_info *ccb; >> struct pm8001_device *pm8001_dev; >> @@ -2287,9 +2285,9 @@ static void mpi_sata_event(struct pm8001_hba_info *pm8001_ha , void *piomb) >> ts->stat = SAS_QUEUE_FULL; >> pm8001_ccb_task_free(pm8001_ha, t, ccb, tag); >> mb();/*ditto*/ >> - spin_unlock_irqrestore(&pm8001_ha->lock, flags); >> + spin_unlock_irq(&pm8001_ha->lock); >> t->task_done(t); >> - spin_lock_irqsave(&pm8001_ha->lock, flags); >> + spin_lock_irq(&pm8001_ha->lock); >> return; >> } >> break; >> @@ -2387,31 +2385,31 @@ static void mpi_sata_event(struct pm8001_hba_info *pm8001_ha , void *piomb) >> ts->stat = SAS_OPEN_TO; >> break; >> } >> - spin_lock_irqsave(&t->task_state_lock, flags); >> + spin_lock_irq(&t->task_state_lock); >MGS> spin_lock_irqsave(&t->task_state_lock, flags); >> t->task_state_flags &= ~SAS_TASK_STATE_PENDING; >> t->task_state_flags &= ~SAS_TASK_AT_INITIATOR; >> t->task_state_flags |= SAS_TASK_STATE_DONE; >> if (unlikely((t->task_state_flags & SAS_TASK_STATE_ABORTED))) { >> - spin_unlock_irqrestore(&t->task_state_lock, flags); >> + spin_unlock_irq(&t->task_state_lock); >MGS> spin_unlock_irqrestore(&t->task_state_lock, flags); >> PM8001_FAIL_DBG(pm8001_ha, >> pm8001_printk("task 0x%p done with io_status 0x%x" >> " resp 0x%x stat 0x%x but aborted by upper layer!\n", >> t, event, ts->resp, ts->stat)); >> pm8001_ccb_task_free(pm8001_ha, t, ccb, tag); >> } else if (t->uldd_task) { >> - spin_unlock_irqrestore(&t->task_state_lock, flags); >> + spin_unlock_irq(&t->task_state_lock); >> pm8001_ccb_task_free(pm8001_ha, t, ccb, tag); >> mb();/* ditto */ >> - spin_unlock_irqrestore(&pm8001_ha->lock, flags); >> + spin_unlock_irq(&pm8001_ha->lock); >> t->task_done(t); >> - spin_lock_irqsave(&pm8001_ha->lock, flags); >> + spin_lock_irq(&pm8001_ha->lock); >> } else if (!t->uldd_task) { >> - spin_unlock_irqrestore(&t->task_state_lock, flags); >> + spin_unlock_irq(&t->task_state_lock); >> pm8001_ccb_task_free(pm8001_ha, t, ccb, tag); >> mb();/*ditto*/ >> - spin_unlock_irqrestore(&pm8001_ha->lock, flags); >> + spin_unlock_irq(&pm8001_ha->lock); >> t->task_done(t); >> - spin_lock_irqsave(&pm8001_ha->lock, flags); >> + spin_lock_irq(&pm8001_ha->lock); >> } >> } > >-- >To unsubscribe from this list: send the line "unsubscribe linux-scsi" in >the body of a message to majordomo@vger.kernel.org >More majordomo info at http://vger.kernel.org/majordomo-info.html > >__________ Information from ESET NOD32 Antivirus, version of virus signature database 5659 (20101129) __________ > >The message was checked by ESET NOD32 Antivirus. > >http://www.eset.com > > >{.n++%ݶw{.n+{G{ayʇڙ,jfhz_(階ݢj"mG?&~iOzv^m ?I