ata/libata-eh.c: introduce ATA_FLAG_NO_LOG_PAGE

This patchset add a new ata port flag ATA_FLAG_NO_LOG_PAGE to be able to blacklist ports/controller which e.g. locks up on a log page read.

This flag is added to the sata_fsl driver which is the first affected one.

The lockup was detected on Freescale P1013/P1022, T4240 using a ATP mSATA.
The device failed during initialisation if the SATA device includes the devslp feature.

With this patchset, we blacklist the fsl sata controller and return a error on any attempt to read a log page. This allows us to access the mSATA.

Changes in v2:
fixed the build issue detected by the kbuild test robot

Andreas Werner (2):
libata-eh.c: Introduce new ata port flag for controller which lockup
on read log page
ata/sata_fsl.c: add ATA_FLAG_NO_LOG_PAGE to blacklist the controller
for log page reads

 drivers/ata/libata-eh.c | 9 +++++++++
 drivers/ata/sata_fsl.c  | 3 ++-
 include/linux/libata.h  | 1 +
 3 files changed, 12 insertions(+), 1 deletion(-)

2.6.2

Some controller lockup on a ata_read_log_page. Add new ata port flag ATA_FLAG_NO_LOG_PAGE which can used to blacklist a controller.

If this flag is set, any attempt to read a log page returns an error without actually issuing the command.

---
 drivers/ata/libata-eh.c | 9 +++++++++
 include/linux/libata.h  | 1 +
 2 files changed, 10 insertions(+)

index cb0508a..c59c2bc 100644
@@ -1505,12 +1505,21 @@ static const char *ata_err_string(unsigned int err_mask)
 unsigned int ata_read_log_page(struct ata_device *dev, u8 log,
 			       u8 page, void *buf, unsigned int sectors)
 {
+	unsigned long ap_flags = dev->link->ap->flags;
 	struct ata_taskfile tf;
 	unsigned int err_mask;
 	bool dma = false;
 
 	DPRINTK("read log page - log 0x%x, page 0x%x\n", log, page);
 
+	/*
+	 * Return error without actually issuing the
+	 * command on controller which e.g. lockup
+	 * on a read log page.
+	 */
+	if (ap_flags & ATA_FLAG_NO_LOG_PAGE)
+		return AC_ERR_DEV;
+
 retry:
 	ata_tf_init(dev, &tf);
 	if (dev->dma_mode && ata_id_has_read_log_dma_ext(dev->id) &&

index 83577f8..600c1e0 100644
@@ -210,6 +210,7 @@ enum {
 	ATA_FLAG_SLAVE_POSS	= (1 << 0), /* host supports slave dev */
 					    /* (doesn't imply presence) */
 	ATA_FLAG_SATA		= (1 << 1),
+	ATA_FLAG_NO_LOG_PAGE	= (1 << 5), /* do not issue log page read */
 	ATA_FLAG_NO_ATAPI	= (1 << 6), /* No ATAPI support */
 	ATA_FLAG_PIO_DMA	= (1 << 7), /* PIO cmds via DMA */
 	ATA_FLAG_PIO_LBA48	= (1 << 8), /* Host DMA engine is LBA28 only */

2.6.2

Every attempt to issue a read log page command lockup the controller. The command is currently sent if the sata device includes the devlsp feature to read out the timing data.
This attempt to read the data, locks up the controller and the device is not recognzied correctly (failed to set xfermode) and cannot be accessed.

This was found on Freescale P1013/P1022 and T4240 CPUs using a ATP IG mSATA 4GB with the devslp feature.

fsl-sata ff718000.sata: Sata FSL Platform/CSB Driver init

[    1.254195] scsi0 : sata_fsl
[    1.256004] ata1: SATA max UDMA/133 irq 74
[    1.370666] fsl-gianfar ethernet.3: enabled errata workarounds, flags: 0x4
[    1.470671] fsl-gianfar ethernet.4: enabled errata workarounds, flags: 0x4
[    1.775584] ata1: Signature Update detected @ 504 msecs
[    1.947594] ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
[    1.948366] ata1.00: ATA-8: ATP IG mSATA, 20150311, max UDMA/133
[    1.948371] ata1.00: 7732368 sectors, multi 0: LBA
[    1.948843] ata1.00: failed to get Identify Device Data, Emask 0x1
[    1.948857] ata1.00: failed to set xfermode (err_mask=0x40)
[    7.467557] ata1: Signature Update detected @ 504 msecs
[    7.639560] ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
[    7.651320] ata1.00: failed to get Identify Device Data, Emask 0x1
[    7.651360] ata1.00: failed to set xfermode (err_mask=0x40)
[    7.655628] ata1: limiting SATA link speed to 1.5 Gbps
[    7.659458] ata1.00: limiting speed to UDMA/133:PIO3
[   13.163554] ata1: Signature Update detected @ 504 msecs
[   13.335558] ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
[   13.347298] ata1.00: failed to get Identify Device Data, Emask 0x1
[   13.347334] ata1.00: failed to set xfermode (err_mask=0x40)
[   13.351601] ata1.00: disabled
[   13.353278] ata1: exception Emask 0x50 SAct 0x0 SErr 0x800 action 0x6 frozen t4
[   13.359281] ata1: SError: { HostInt }
[   13.361644] ata1: hard resetting link

---
 drivers/ata/sata_fsl.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

index 5389579..a723ae9 100644
@@ -45,7 +45,8 @@ enum {
 	SATA_FSL_MAX_PRD_DIRECT	= 16,	/* Direct PRDT entries */
 
 	SATA_FSL_HOST_FLAGS	= (ATA_FLAG_SATA | ATA_FLAG_PIO_DMA |
-				ATA_FLAG_PMP | ATA_FLAG_NCQ | ATA_FLAG_AN),
+				   ATA_FLAG_PMP | ATA_FLAG_NCQ |
+				   ATA_FLAG_AN | ATA_FLAG_NO_LOG_PAGE),
 
 	SATA_FSL_MAX_CMDS	= SATA_FSL_QUEUE_DEPTH,
 	SATA_FSL_CMD_HDR_SIZE	= 16,	/* 4 DWORDS */

2.6.2

Applied 1-2 to libata/for-4.4-fixes.

Thanks.

tejun

Thanks Tejun for the discussion and that the patch was applied :-)

Regards
Andy