Delete extra checks for the ATA_DFLAG_CDL_ENABLED flag that prevent
SET FEATURES command from being issued to a drive when NCQ commands
are active.
ata_mselect_control_ata_feature() sets / clears the ATA_DFLAG_CDL_ENABLED
flag during the translation of MODE SELECT to SET FEATURES. If SET FEATURES
gets deferred due to outstanding NCQ commands, the original MODE SELECT
command will be re-queued. When the re-queued MODE SELECT goes through
the ata_mselect_control_ata_feature() translation again, SET FEATURES
will not be issued because ATA_DFLAG_CDL_ENABLED has been already set or
cleared by the initial translation of MODE SELECT.
The ATA_DFLAG_CDL_ENABLED checks in ata_mselect_control_ata_feature()
are safe to remove because scsi_cdl_enable() implements a similar logic
that avoids enabling CDL if it has been enabled already.
Fixes: 17e897a45675 ("ata: libata-scsi: Improve CDL control")
Signed-off-by: Igor Pylypiv <ipylypiv@xxxxxxxxxx>
---
Changes from v1:
- Changed the patch from revert to fixup.
- Restored debug logs and the comment about mutual exclusivity with
NCQ priority.
- Dropped cc to stable and added fixes tag instead.
drivers/ata/libata-scsi.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 57f674f51b0c..2ded5e476d6e 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -3904,21 +3904,16 @@ static int ata_mselect_control_ata_feature(struct ata_queued_cmd *qc,
/* Check cdl_ctrl */
switch (buf[0] & 0x03) {
case 0:
- /* Disable CDL if it is enabled */
- if (!(dev->flags & ATA_DFLAG_CDL_ENABLED))
- return 0;
+ /* Disable CDL */
ata_dev_dbg(dev, "Disabling CDL\n");
cdl_action = 0;
dev->flags &= ~ATA_DFLAG_CDL_ENABLED;
break;
case 0x02:
/*
- * Enable CDL if not already enabled. Since this is mutually
- * exclusive with NCQ priority, allow this only if NCQ priority
- * is disabled.
+ * Enable CDL. Since CDL is mutually exclusive with NCQ
+ * priority, allow this only if NCQ priority is disabled.
*/
- if (dev->flags & ATA_DFLAG_CDL_ENABLED)
- return 0;
if (dev->flags & ATA_DFLAG_NCQ_PRIO_ENABLED) {
ata_dev_err(dev,
"NCQ priority must be disabled to enable CDL\n");
--
2.51.0.rc0.215.g125493bb4a-goog
