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SubjectRe: [PATCH v3 2/5] [SCSI] ufshcd: UFS UTP Transfer requests handling
Santosh Y wrote:
> + ucd_cmd_ptr->exp_data_transfer_len =
> + cpu_to_be32(lrbp->cmd->transfersize);
> +
> + memcpy(ucd_cmd_ptr->cdb,
> + lrbp->cmd->cmnd,
> + (min_t(unsigned short,
> + lrbp->cmd->cmd_len,
> + MAX_CDB_SIZE)));

"Exptected Data Transfer Length" field contains a value that
represents the number of bytes that are required to complete the
SCSI command request and the number of bytes that the Initiator
expects to be transferred to/from the Target.
(JEDEC Standard 220 Table7-7)
On the other hand, "transfersize" in a scsi_cmnd struct is trimmed
to the sector size when requested transfer length exceeds it.
You may derive the actual transfer length from SCSI command itself like following.

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index feffe65..e63fecb 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -647,6 +647,34 @@ static void ufshcd_compose_upiu(struct ufshcd_lrb *lrbp)
(min_t(unsigned short,
lrbp->cmd->cmd_len,
MAX_CDB_SIZE)));
+
+ /* Overwrite exptected transfer length by using TRANSFER_LENGTH in SCSI commands */
+ switch(ucd_cmd_ptr->cdb[0]) {
+ case READ_6:
+ case WRITE_6:
+ ucd_cmd_ptr->exp_data_transfer_len =
+ cpu_to_be32(lrbp->cmd->transfersize *
+ ucd_cmd_ptr->cdb[4]);
+ break;
+ case READ_10:
+ case WRITE_10:
+ ucd_cmd_ptr->exp_data_transfer_len =
+ cpu_to_be32(lrbp->cmd->transfersize *
+ ((ucd_cmd_ptr->cdb[7] << 8) |
+ ucd_cmd_ptr->cdb[8]));
+ break;
+ case READ_12:
+ case WRITE_12:
+ ucd_cmd_ptr->exp_data_transfer_len =
+ cpu_to_be32(lrbp->cmd->transfersize *
+ ((ucd_cmd_ptr->cdb[10] << 24) |
+ (ucd_cmd_ptr->cdb[11] << 16) |
+ (ucd_cmd_ptr->cdb[12] << 8) |
+ ucd_cmd_ptr->cdb[13]));
+ break;
+ default:
+ break;
+ }
break;
case UTP_CMD_TYPE_DEV_MANAGE:
/* For query function implementation */


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