This reverts commit 17e897a456752ec9c2d7afb3d9baf268b442451b.
The extra checks for the ATA_DFLAG_CDL_ENABLED flag 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 already enabled.
Cc: stable@vger.kernel.org Signed-off-by: Igor Pylypiv ipylypiv@google.com --- drivers/ata/libata-scsi.c | 14 ++------------ 1 file changed, 2 insertions(+), 12 deletions(-)
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index 57f674f51b0c..856eabfd5a17 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -3904,27 +3904,17 @@ 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; - ata_dev_dbg(dev, "Disabling CDL\n"); + /* Disable CDL */ 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. - */ - if (dev->flags & ATA_DFLAG_CDL_ENABLED) - return 0; + /* Enable CDL T2A/T2B: NCQ priority must be disabled */ if (dev->flags & ATA_DFLAG_NCQ_PRIO_ENABLED) { ata_dev_err(dev, "NCQ priority must be disabled to enable CDL\n"); return -EINVAL; } - ata_dev_dbg(dev, "Enabling CDL\n"); cdl_action = 1; dev->flags |= ATA_DFLAG_CDL_ENABLED; break;