[PATCH] ata: libata-eh: Increase STANDBY IMMEDIATE timeout

[Matt Vollrath <tactii@gmail.com>]

Correct a previous change (see Fixes) which reduced the standby timeout
from 30 to 5 seconds. Increase it to 15 seconds.

I was troubleshooting an error spotted during system suspend:

    [ 1217.152867] ata1.00: Entering standby power mode
    [ 1222.322948] ata1.00: qc timeout after 5000 msecs (cmd 0xe0)
    [ 1222.324010] ata1.00: STANDBY IMMEDIATE failed (err_mask=0x4)

This drive is a Samsung 870 EVO SSD in good SMART standing, and I wasn't
aware of any reason it should be taking so long to standby. The issue is
intermittent, but I observed it sometimes taking 7 seconds to manually
standby. I assume this was interruption of background maintenance after
a power outage.

As a desktop user, I would prefer to wait the extra 2 seconds at suspend
to let the drive finish its business rather than drop the rails from
under it.

The change from 30 to 5 seconds was implicit when switching suspend
from START STOP UNIT to an internal command with no timeout table entry.
No reason was stated for the change.

Fixes: aa3998dbeb3a ("ata: libata-scsi: Disable scsi device manage_system_start_stop")
Cc: stable@vger.kernel.org
Signed-off-by: Matt Vollrath <tactii@gmail.com>
Assisted-by: Claude:claude-5-fable
---
 drivers/ata/libata-eh.c | 8 ++++++++
 include/linux/libata.h  | 2 +-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 05df7ea6954a..46947ed0c657 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -106,6 +106,12 @@ static const unsigned int ata_eh_flush_timeouts[] = {
 	UINT_MAX,
 };
 
+static const unsigned int ata_eh_standby_timeouts[] = {
+	15000,	/* Some drives may be slow to standby */
+	/* but don't hold up a suspend too long waiting for them */
+	UINT_MAX,
+};
+
 static const unsigned int ata_eh_other_timeouts[] = {
 	 5000,	/* same rationale as identify timeout */
 	10000,	/* ditto */
@@ -147,6 +153,8 @@ ata_eh_cmd_timeout_table[ATA_EH_CMD_TIMEOUT_TABLE_SIZE] = {
 	  .timeouts = ata_eh_other_timeouts, },
 	{ .commands = CMDS(ATA_CMD_FLUSH, ATA_CMD_FLUSH_EXT),
 	  .timeouts = ata_eh_flush_timeouts },
+	{ .commands = CMDS(ATA_CMD_STANDBYNOW1),
+	  .timeouts = ata_eh_standby_timeouts },
 	{ .commands = CMDS(ATA_CMD_VERIFY),
 	  .timeouts = ata_eh_reset_timeouts },
 };
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 96e626d6a7ca..6c0d385b2cde 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -425,7 +425,7 @@ enum {
 	/* This should match the actual table size of
 	 * ata_eh_cmd_timeout_table in libata-eh.c.
 	 */
-	ATA_EH_CMD_TIMEOUT_TABLE_SIZE = 8,
+	ATA_EH_CMD_TIMEOUT_TABLE_SIZE = 9,
 
 	/* User visible DMA mask for DMA control. DO NOT renumber. */
 	ATA_DMA_MASK_ATA	= (1 << 0),	/* DMA on ATA Disk */

base-commit: 4d99a91574c420decab56cc880fad0dc15b8a7a3
-- 
2.43.0