On 7/26/2013 7:16 PM, Seungwon Jeon wrote:
Except for 'GOOD' and 'CHECK CONDITION', other status value
in Response UPIU may or may contain sense data. If a non-zero
value is in the Data Segment Length field, it means that UPIU
has Sense Data in the Data Segment area.

Signed-off-by: Seungwon Jeon <[email protected]>
---
  drivers/scsi/ufs/ufs.h    |    1 +
  drivers/scsi/ufs/ufshcd.c |   27 +++++++++++++++++++--------
  2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
index 139bc06..737c31b 100644
--- a/drivers/scsi/ufs/ufs.h
+++ b/drivers/scsi/ufs/ufs.h
@@ -114,6 +114,7 @@ enum {
        MASK_SCSI_STATUS        = 0xFF,
        MASK_TASK_RESPONSE      = 0xFF00,
        MASK_RSP_UPIU_RESULT    = 0xFFFF,
+       MASK_RSP_UPIU_DATA_SEG_LEN      = 0xFFFF,
  };

  /* Task management service response */
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 4cf3a2d..688ae0e 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -218,6 +218,20 @@ ufshcd_get_rsp_upiu_result(struct utp_upiu_rsp 
*ucd_rsp_ptr)
        return be32_to_cpu(ucd_rsp_ptr->header.dword_1) & MASK_RSP_UPIU_RESULT;
  }

+/*
+ * ufshcd_get_rsp_upiu_data_seg_len - Get the data segment length
+ *                             from response UPIU
+ * @ucd_rsp_ptr: pointer to response UPIU
+ *
+ * Return the data segment length.
+ */
+static inline int
+ufshcd_get_rsp_upiu_data_seg_len(struct utp_upiu_rsp *ucd_rsp_ptr)
+{
+       return be32_to_cpu(ucd_rsp_ptr->header.dword_2) &
+               MASK_RSP_UPIU_DATA_SEG_LEN;
+}
+
  /**
   * ufshcd_config_int_aggr - Configure interrupt aggregation values.
   *            Currently there is no use case where we want to configure
@@ -298,7 +312,8 @@ void ufshcd_send_command(struct ufs_hba *hba, unsigned int 
task_tag)
  static inline void ufshcd_copy_sense_data(struct ufshcd_lrb *lrbp)
  {
        int len;
-       if (lrbp->sense_buffer) {
+       if (lrbp->sense_buffer &&
+           !ufshcd_get_rsp_upiu_data_seg_len(lrbp->ucd_rsp_ptr)) {
                len = be16_to_cpu(lrbp->ucd_rsp_ptr->sense_data_len);
                memcpy(lrbp->sense_buffer,
                        lrbp->ucd_rsp_ptr->sense_data,
@@ -1156,21 +1171,17 @@ ufshcd_scsi_cmd_status(struct ufshcd_lrb *lrbp, int 
scsi_status)
                          SAM_STAT_CHECK_CONDITION;

The whole function is doing things wrong. It is redundant to interpret
the scsi_status at the LLD layer and make decisions while otherwise the
SCSI layer anyway knows how handle them properly.

Please see scsi_decide_disposition().

Ideally, this is what we should do -
if (response_upiu_sense_data_len > 0 && lrbp->sense_buffer) {
 ufshcd_copy_sense_data();
}
result = set_host_byte(DID_OK) |
                set_msg_byte(COMMAND_COMPLETE) |
                (scsi_status & 0xff);

                ufshcd_copy_sense_data(lrbp);
                break;
-       case SAM_STAT_BUSY:
-               result |= SAM_STAT_BUSY;
-               break;
        case SAM_STAT_TASK_SET_FULL:
-
                /*
                 * If a LUN reports SAM_STAT_TASK_SET_FULL, then the LUN queue
                 * depth needs to be adjusted to the exact number of
                 * outstanding commands the LUN can handle at any given time.
                 */
                ufshcd_adjust_lun_qdepth(lrbp->cmd);
-               result |= SAM_STAT_TASK_SET_FULL;
-               break;
+       case SAM_STAT_BUSY:
        case SAM_STAT_TASK_ABORTED:
-               result |= SAM_STAT_TASK_ABORTED;
+               result |= scsi_status;
+               ufshcd_copy_sense_data(lrbp);
                break;
        default:
                result |= DID_ERROR << 16;


--
Regards,
Sujit
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