From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH v3] ahci_xgene: Fix the dma state machine lockup for the ATA_CMD_SMART PIO mode command. Date: Mon, 02 Feb 2015 22:44:15 +0300 Message-ID: <54CFD38F.2060803@cogentembedded.com> References: <1422900439-5541-1-git-send-email-stripathi@apm.com> <1422900439-5541-2-git-send-email-stripathi@apm.com> <54CFCC28.6050609@cogentembedded.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-scsi-owner@vger.kernel.org To: Suman Tripathi Cc: Olof Johansson , Tejun Heo , Arnd Bergmann , Linux SCSI List , "linux-ide@vger.kernel.org" , "devicetree@vger.kernel.org" , linux-arm-kernel , Mark Langsdorf , Jon Masters , patches List-Id: linux-ide@vger.kernel.org On 02/02/2015 10:37 PM, Suman Tripathi wrote: Ugh, please avoid using HTML when posting to the lists hosted on vger.kernel.org -- it's configured to ignore such mails AFAIK. >>> This patch addresses the issue with ATA_CMD_SMART pio mode >>> command for enumeration and device detection with ATA devices. >>> The X-Gene AHCI controller has an errata in which it cannot clear >>> the BSY bit after the PIO setup FIS. The dma state machine enters >> Hum, if this happens after every PIO command (PIO setup FISes are not >> specific to the command, right?), perhaps it would make more sense to record >> the *protocol* used by the last command? > No it happens for IDENTIFY DEVICE, ATA_CMD_PACKET and ATA_CMD_SMART commands . > It is actually the commands associated with a BSY bit clearing. I don't understand that -- BSY bit is cleared for *every* command, either at the end of it, or along with setting the DRQ bit for PIO data transfer. >>> CMFatalErrorUpdate state and locks up. It is the same issue as >>> in the commit 2a0bdff6b958d1b2523d2754b6cd5e__0ea4053016 (ahci-xgene: >>> fix the dma state machine lockup for the IDENTIFY DEVICE PIO mode >>> command). >> [...] >>> Signed-off-by: Suman Tripathi > >>> Reported-by: Mark Langsdorf >> > >>> MBR, Sergei