[PATCH v2 1/2] USB: storage: don't insert sane sense for SPC3+ when bad sense specified

[Icenowy Zheng]

Currently the code will set US_FL_SANE_SENSE flag unconditionally if
device claims SPC3+, however we should allow US_FL_BAD_SENSE flag to
prevent this behavior, because SMI SM3350 UFS-USB bridge controller,
which claims SPC4, will show strange behavior with 96-byte sense
(put the chip into a wrong state that cannot read/write anything).

Check the presence of US_FL_BAD_SENSE when assuming US_FL_SANE_SENSE on
SPC4+ devices.

Signed-off-by: Icenowy Zheng <icenowy@xxxxxxx>
---
Changes in v2:
- Changed the comment to note the check.

 drivers/usb/storage/scsiglue.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c
index fde2e71a6ade..a73ea495d5a7 100644
--- a/drivers/usb/storage/scsiglue.c
+++ b/drivers/usb/storage/scsiglue.c
@@ -235,8 +235,12 @@ static int slave_configure(struct scsi_device *sdev)
 		if (!(us->fflags & US_FL_NEEDS_CAP16))
 			sdev->try_rc_10_first = 1;
 
-		/* assume SPC3 or latter devices support sense size > 18 */
-		if (sdev->scsi_level > SCSI_SPC_2)
+		/*
+		 * assume SPC3 or latter devices support sense size > 18
+		 * unless US_FL_BAD_SENSE quirk is specified.
+		 */
+		if (sdev->scsi_level > SCSI_SPC_2 &&
+		    !(us->fflags & US_FL_BAD_SENSE))
 			us->fflags |= US_FL_SANE_SENSE;
 
 		/*
-- 
2.18.1