From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH v3] ahci_xgene: Fix the dma state machine lockup for the ATA_CMD_SMART PIO mode command. Date: Tue, 3 Feb 2015 11:18:09 -0500 Message-ID: <20150203161809.GG19463@htj.dyndns.org> References: <1422900439-5541-1-git-send-email-stripathi@apm.com> <1422900439-5541-2-git-send-email-stripathi@apm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1422900439-5541-2-git-send-email-stripathi@apm.com> Sender: linux-ide-owner@vger.kernel.org To: Suman Tripathi Cc: olof@lixom.net, arnd@arndb.de, linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, mlangsdo@redhat.com, jcm@redhat.com, patches@apm.com List-Id: devicetree@vger.kernel.org On Mon, Feb 02, 2015 at 11:37:19PM +0530, Suman Tripathi wrote: > 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 > CMFatalErrorUpdate state and locks up. It is the same issue as > in the commit 2a0bdff6b958d1b2523d2754b6cd5e0ea4053016 (ahci-xgene: The right format is 2a0bdff6b958 ("ahci-xgene: fix the dma state machine lockup for the IDENTIFY DEVICE PIO mode command"). > fix the dma state machine lockup for the IDENTIFY DEVICE PIO mode > command). > > For example : without this patch it results in READ DMA command failure > as shown below : > > [ 126.700072] ata2.00: exception Emask 0x0 SAct 0x0 > SErr 0x0 action 0x6 frozen > [ 126.707089] ata2.00: failed command: READ DMA > [ 126.711426] ata2.00: cmd c8/00:08:00:55:57/00:00:00:00:00/e1 tag 1 > dma 4096 in > [ 126.711426] res 40/00:ff:00:00:00/00:00:00:00:00/40 Emask > 0x4 (timeout) > [ 126.725956] ata2.00: status: { DRDY } > > Signed-off-by: Suman Tripathi > Reported-by: Mark Langsdorf Applied to libata/for-3.19-fixes. Thanks. -- tejun