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 <stripathi@xxxxxxx> > Reported-by: Mark Langsdorf <mlangsdo@xxxxxxxxxx> Applied to libata/for-3.19-fixes. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html