[040/141] libata: make ata_exec_internal_sg honor DMADIR

Steven Rostedt
2013-07-03T18:53:44Z

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3.6.11.6 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Vincent Pelletier <plr.vincent@gmail.com>

[ Upstream commit e771451c0a831d96a7c14b0ca8a8ec671d98567b ]

libata honors DMADIR for regular commands, but not for internal commands
used (among other) during device initialisation.

This makes SATA-host-to-PATA-device bridges based on Silicon Image SiL3611
(such as "Abit Serillel 2") end up disabled when used with an ATAPI device
after a few tries.

Log output of the bridge being hot-plugged with an ATAPI drive:

[ 9631.212901] ata1: exception Emask 0x10 SAct 0x0 SErr 0x40c0000 action 0xe frozen
[ 9631.212913] ata1: irq_stat 0x00000040, connection status changed
[ 9631.212923] ata1: SError: { CommWake 10B8B DevExch }
[ 9631.212939] ata1: hard resetting link
[ 9632.104962] ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
[ 9632.106393] ata1.00: ATAPI: PIONEER DVD-RW DVR-115, 1.06, max UDMA/33
[ 9632.106407] ata1.00: applying bridge limits
[ 9632.108151] ata1.00: configured for UDMA/33
[ 9637.105303] ata1.00: qc timeout (cmd 0xa0)
[ 9637.105324] ata1.00: failed to clear UNIT ATTENTION (err_mask=0x5)
[ 9637.105335] ata1: hard resetting link
[ 9638.044599] ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
[ 9638.047878] ata1.00: configured for UDMA/33
[ 9643.044933] ata1.00: qc timeout (cmd 0xa0)
[ 9643.044953] ata1.00: failed to clear UNIT ATTENTION (err_mask=0x5)
[ 9643.044963] ata1: limiting SATA link speed to 1.5 Gbps
[ 9643.044971] ata1.00: limiting speed to UDMA/33:PIO3
[ 9643.044979] ata1: hard resetting link
[ 9643.984225] ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 310)
[ 9643.987471] ata1.00: configured for UDMA/33
[ 9648.984591] ata1.00: qc timeout (cmd 0xa0)
[ 9648.984612] ata1.00: failed to clear UNIT ATTENTION (err_mask=0x5)
[ 9648.984619] ata1.00: disabled
[ 9649.000593] ata1: hard resetting link
[ 9649.939902] ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 310)
[ 9649.955864] ata1: EH complete

With this patch, the drive enumerates correctly when libata is loaded with
atapi_dmadir=1:

[ 9891.810863] ata1: exception Emask 0x10 SAct 0x0 SErr 0x40c0000 action 0xe frozen
[ 9891.810874] ata1: irq_stat 0x00000040, connection status changed
[ 9891.810884] ata1: SError: { CommWake 10B8B DevExch }
[ 9891.810900] ata1: hard resetting link
[ 9892.762105] ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
[ 9892.763544] ata1.00: ATAPI: PIONEER DVD-RW DVR-115, 1.06, max UDMA/33, DMADIR
[ 9892.763558] ata1.00: applying bridge limits
[ 9892.765393] ata1.00: configured for UDMA/33
[ 9892.786063] ata1: EH complete
[ 9892.792062] scsi 0:0:0:0: CD-ROM PIONEER DVD-RW DVR-115 1.06 PQ: 0 ANSI: 5
[ 9892.798455] sr2: scsi3-mmc drive: 12x/12x writer dvd-ram cd/rw xa/form2 cdda tray
[ 9892.798837] sr 0:0:0:0: Attached scsi CD-ROM sr2
[ 9892.799109] sr 0:0:0:0: Attached scsi generic sg6 type 5

Based on a patch by Csaba Halász <csaba.halasz@gmail.com> on linux-ide:
http://marc.info/?l=linux-ide&m=136121147832295&w=2

tj: minor formatting changes.

Signed-off-by: Vincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
drivers/ata/libata-core.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 3e351e7..b76e6ea 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -1601,6 +1601,12 @@ unsigned ata_exec_internal_sg(struct ata_device *dev,
qc->tf = *tf;
if (cdb)
memcpy(qc->cdb, cdb, ATAPI_CDB_LEN);
+
+ /* some SATA bridges need us to indicate data xfer direction */
+ if (tf->protocol == ATAPI_PROT_DMA && (dev->flags & ATA_DFLAG_DMADIR) &&
+ dma_dir == DMA_FROM_DEVICE)
+ qc->tf.feature |= ATAPI_DMADIR;
+
qc->flags |= ATA_QCFLAG_RESULT_TF;
qc->dma_dir = dma_dir;
if (dma_dir != DMA_NONE) {
--
1.7.10.4