[PATCH][SCSI] scsi: ufs: get a TM service response from the correct offset

[PATCH][SCSI] scsi: ufs: get a TM service response from the correct offset

[Kiwoong Kim]

From: Kiwoong Kim <kwmad.kim@samsung.com>

When any UFS host controller receives a TM(Task Management)
response from a UFS device,
UFS driver has been recognize like receiving a message of
"Task Management Function Complete"(00h) in all cases, so far.
That means there is no pending task for a tag of the TM request
sent before in the UFS device.
That's because the byte offset 6 in TM response which has been used
to get a TM service response so far
represents just whether or not a TM transmission passes.

Regarding UFS spec, the correct byte offset to
get TM service response is 15, not 6.

I tested that UFS driver responds properly for the TM response
>From a UFS device with an reference board with exynos8890, as follow:
No pending task -> Task Management Function Complete (00h)
Pending task -> Task Management Function Succeeded (08h)

Signed-off-by: Kiwoong Kim <kwmad.kim@samsung.com>
Signed-off-by: HeonGwang Chu <hg.chu@samsung.com>
Tested-by: : Kiwoong Kim <kwmad.kim@samsung.com>
---
 drivers/scsi/ufs/ufs.h    |    1 +
 drivers/scsi/ufs/ufshcd.c |    4 ++--
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
index 42c459a..89c121e 100644
--- a/drivers/scsi/ufs/ufs.h
+++ b/drivers/scsi/ufs/ufs.h
@@ -295,6 +295,7 @@ enum {
        MASK_QUERY_DATA_SEG_LEN         = 0xFFFF,
        MASK_RSP_UPIU_DATA_SEG_LEN      = 0xFFFF,
        MASK_RSP_EXCEPTION_EVENT        = 0x10000,
+       MASK_TM_SERVICE_RESP            = 0xFF,
 };

 /* Task management service response */
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index e8a706b..c641cd3 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -3013,8 +3013,8 @@ static int ufshcd_task_req_compl(struct ufs_hba *hba, u32 index, u8 *resp)
        if (ocs_value == OCS_SUCCESS) {
                task_rsp_upiup = (struct utp_upiu_task_rsp *)
                                task_req_descp[index].task_rsp_upiu;
-               task_result = be32_to_cpu(task_rsp_upiup->header.dword_1);
-               task_result = ((task_result & MASK_TASK_RESPONSE) >> 8);
+               task_result = be32_to_cpu(task_rsp_upiup->output_param1);
+               task_result = task_result & MASK_TM_SERVICE_RESP;
                if (resp)
                        *resp = (u8)task_result;
        } else {
--
1.7.9.5

Re: [PATCH][SCSI] scsi: ufs: get a TM service response from the correct offset

[Martin K. Petersen]

>>>>> "Kiwoong" == Kiwoong Kim <kwmad.kim@samsung.com> writes:

Kiwoong,

Kiwoong> When any UFS host controller receives a TM(Task Management)
Kiwoong> response from a UFS device, UFS driver has been recognize like
Kiwoong> receiving a message of "Task Management Function Complete"(00h)
Kiwoong> in all cases, so far.  That means there is no pending task for
Kiwoong> a tag of the TM request sent before in the UFS device.  That's
Kiwoong> because the byte offset 6 in TM response which has been used to
Kiwoong> get a TM service response so far represents just whether or not
Kiwoong> a TM transmission passes.

Kiwoong> Regarding UFS spec, the correct byte offset to get TM service
Kiwoong> response is 15, not 6.

Kiwoong> I tested that UFS driver responds properly for the TM response
Kiwoong> From a UFS device with an reference board with exynos8890, as
Kiwoong> follow: No pending task -> Task Management Function Complete
Kiwoong> (00h) Pending task -> Task Management Function Succeeded (08h)

Went through the hoops to verify this in the spec since nobody stepped
up to review. In the future please make sure to submit patches against
my scsi for-next git repo. I had to apply the patch by hand.

Thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH][SCSI] scsi: ufs: get a TM service response from the correct offset

[subhashj]

Hi Kiwoong Kim,

This is a good catch, Looks good to me.
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>

Thanks,
Subhash

On 2016-09-08 16:22, Kiwoong Kim wrote:
> From: Kiwoong Kim <kwmad.kim@samsung.com>
> 
> When any UFS host controller receives a TM(Task Management)
> response from a UFS device,
> UFS driver has been recognize like receiving a message of
> "Task Management Function Complete"(00h) in all cases, so far.
> That means there is no pending task for a tag of the TM request
> sent before in the UFS device.
> That's because the byte offset 6 in TM response which has been used
> to get a TM service response so far
> represents just whether or not a TM transmission passes.
> 
> Regarding UFS spec, the correct byte offset to
> get TM service response is 15, not 6.
> 
> I tested that UFS driver responds properly for the TM response
> From a UFS device with an reference board with exynos8890, as follow:
> No pending task -> Task Management Function Complete (00h)
> Pending task -> Task Management Function Succeeded (08h)
> 
> Signed-off-by: Kiwoong Kim <kwmad.kim@samsung.com>
> Signed-off-by: HeonGwang Chu <hg.chu@samsung.com>
> Tested-by: : Kiwoong Kim <kwmad.kim@samsung.com>
> ---
>  drivers/scsi/ufs/ufs.h    |    1 +
>  drivers/scsi/ufs/ufshcd.c |    4 ++--
>  2 files changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
> index 42c459a..89c121e 100644
> --- a/drivers/scsi/ufs/ufs.h
> +++ b/drivers/scsi/ufs/ufs.h
> @@ -295,6 +295,7 @@ enum {
>         MASK_QUERY_DATA_SEG_LEN         = 0xFFFF,
>         MASK_RSP_UPIU_DATA_SEG_LEN      = 0xFFFF,
>         MASK_RSP_EXCEPTION_EVENT        = 0x10000,
> +       MASK_TM_SERVICE_RESP            = 0xFF,
>  };
> 
>  /* Task management service response */
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index e8a706b..c641cd3 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -3013,8 +3013,8 @@ static int ufshcd_task_req_compl(struct ufs_hba
> *hba, u32 index, u8 *resp)
>         if (ocs_value == OCS_SUCCESS) {
>                 task_rsp_upiup = (struct utp_upiu_task_rsp *)
>                                 task_req_descp[index].task_rsp_upiu;
> -               task_result = 
> be32_to_cpu(task_rsp_upiup->header.dword_1);
> -               task_result = ((task_result & MASK_TASK_RESPONSE) >> 
> 8);
> +               task_result = 
> be32_to_cpu(task_rsp_upiup->output_param1);
> +               task_result = task_result & MASK_TM_SERVICE_RESP;
>                 if (resp)
>                         *resp = (u8)task_result;
>         } else {
> --
> 1.7.9.5
> 
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