scsi: ufs: Fix residual handling

Only call scsi_set_resid() in case of an underflow. Do not call
scsi_set_resid() in case of an overflow.

Cc: Avri Altman <avri.altman@wdc.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Fixes: cb38845d90fc ("scsi: ufs: core: Set the residual byte count")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230724200843.3376570-2-bvanassche@acm.org
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index c394dc5..27e1a49 100644 (file)
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -5222,9 +5222,17 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp,
        int result = 0;
        int scsi_status;
        enum utp_ocs ocs;
+       u8 upiu_flags;
+       u32 resid;
 
-       scsi_set_resid(lrbp->cmd,
-               be32_to_cpu(lrbp->ucd_rsp_ptr->sr.residual_transfer_count));
+       upiu_flags = be32_to_cpu(lrbp->ucd_rsp_ptr->header.dword_0) >> 16;
+       resid = be32_to_cpu(lrbp->ucd_rsp_ptr->sr.residual_transfer_count);
+       /*
+        * Test !overflow instead of underflow to support UFS devices that do
+        * not set either flag.
+        */
+       if (resid && !(upiu_flags & UPIU_RSP_FLAG_OVERFLOW))
+               scsi_set_resid(lrbp->cmd, resid);
 
        /* overall command status of utrd */
        ocs = ufshcd_get_tr_ocs(lrbp, cqe);

diff --git a/include/ufs/ufs.h b/include/ufs/ufs.h
index 0dd546a..c789252 100644 (file)
--- a/include/ufs/ufs.h
+++ b/include/ufs/ufs.h
@@ -104,6 +104,12 @@ enum {
        UPIU_CMD_FLAGS_READ     = 0x40,
 };
 
+/* UPIU response flags */
+enum {
+       UPIU_RSP_FLAG_UNDERFLOW = 0x20,
+       UPIU_RSP_FLAG_OVERFLOW  = 0x40,
+};
+
 /* UPIU Task Attributes */
 enum {
        UPIU_TASK_ATTR_SIMPLE   = 0x00,