From mboxrd@z Thu Jan 1 00:00:00 1970 From: tj@kernel.org (Tejun Heo) Date: Thu, 19 Jun 2014 10:21:48 -0400 Subject: [PATCH v3 2/2] ata: Fix the dma state machine lockup for the IDENTIFY DEVICE PIO mode command. In-Reply-To: References: <1403160654-31612-1-git-send-email-stripathi@apm.com> <20140619141047.GA26904@htj.dyndns.org> Message-ID: <20140619142148.GD26904@htj.dyndns.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Jun 19, 2014 at 07:44:28PM +0530, Suman Tripathi wrote: > Hi Tejun, > > On Thu, Jun 19, 2014 at 12:20:54PM +0530, Suman Tripathi wrote: > > + /* > > + * Restart the dma engine if the last cmd issued > > + * is IDENTIFY DEVICE command > > + */ > > + if (unlikely(ctx->last_cmd[ap->port_no] == ATA_CMD_ID_ATA)) > > + ahci_restart_engine(ap); > > Is it really only for IDENTIFY? Are other PIO commands okay? > [Suman] : We root cause it , It is the IDENTIFY DEVICE command . Other are > ok > Theprevious version applied it to all PIO commands, right? > [suman] : The v2 contains only the IDENTIFY DEVICE. The v1 is contains for > all PIO commands and that didn't work because the ERRATA mentions that it > happens for the IDENTIFY DEVICE command. So, it's just ATA_CMD_ID_ATA and ATA_CMD_ID_ATAPI is okay? That's kinda weird. -- tejun