>
> 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@xxxxxxx>
> Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> Fixes: cb38845d90fc ("scsi: ufs: core: Set the residual byte count")
> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
> ---
> drivers/ufs/core/ufshcd.c | 19 ++++++++++++++++---
> include/ufs/ufs.h | 6 ++++++
> 2 files changed, 22 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index
> e31242fe0518..b27372f9b488 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -5241,12 +5241,25 @@ static inline int ufshcd_transfer_rsp_status(struct
> ufs_hba *hba, struct ufshcd_lrb *lrbp,
> struct cq_entry *cqe) {
> + bool overflow, underflow;
> + u8 upiu_flags;
> int result = 0;
> int scsi_status;
> enum utp_ocs ocs;
> -
> - scsi_set_resid(lrbp->cmd,
> - be32_to_cpu(lrbp->ucd_rsp_ptr->sr.residual_transfer_count));
> + u32 resid;
> +
> + upiu_flags = be32_to_cpu(lrbp->ucd_rsp_ptr->header.dword_0) >> 16;
> + overflow = upiu_flags & UPIU_RSP_FLAG_OVERFLOW;
> + underflow = upiu_flags & UPIU_RSP_FLAG_UNDERFLOW;
> + resid = be32_to_cpu(lrbp->ucd_rsp_ptr->sr.residual_transfer_count);
> + WARN_ON_ONCE(overflow && underflow);
> + WARN_ON_ONCE(!overflow && !underflow && resid);
Do we really need to debug the hw? - see Table 10.16 (3.1 spec).
Thanks,
Avri
> + /*
> + * Test !overflow instead of underflow to support UFS devices that do
> + * not set either flag.
> + */
> + if (!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 8316e2408ac3..bee5ccc6e7ce 100644
> --- 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,
