RE: [PATCH v6 05/10] scsi: ufs: add quirk to fix abnormal ocs fatal error

[Avri Altman <Avri.Altman@wdc.com>]

> 
> From: Kiwoong Kim <kwmad.kim@samsung.com>
> 
> Some architectures determines if fatal error for OCS
> occurrs to check status in response upiu. This patch
Typo - occurs

> is to prevent from reporting command results with that.
> 
> Signed-off-by: Kiwoong Kim <kwmad.kim@samsung.com>
> Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
> ---
>  drivers/scsi/ufs/ufshcd.c | 6 ++++++
>  drivers/scsi/ufs/ufshcd.h | 6 ++++++
>  2 files changed, 12 insertions(+)
> 
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index b32fcedcdcb9..8c07caff0a5c 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -4794,6 +4794,12 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba,
> struct ufshcd_lrb *lrbp)
>         /* overall command status of utrd */
>         ocs = ufshcd_get_tr_ocs(lrbp);
> 
> +       if (hba->quirks & UFSHCD_QUIRK_BROKEN_OCS_FATAL_ERROR) {
> +               if (be32_to_cpu(lrbp->ucd_rsp_ptr->header.dword_1) &
> +                                       MASK_RSP_UPIU_RESULT)
> +                       ocs = OCS_SUCCESS;
> +       }
> +
Not sure that I follow what this quirk is all about.
Your code overrides ocs by open coding ufshcd_get_rsp_upiu_result.

Normally OCS is in utp transfer req descriptor, dword 2, bits 0..7.
My understanding from your description, is that some fatal error might occur,
But the host controller does not report it, and it still needs to be checked in the response upiu.
Evidently you are not doing so.
Please elaborate your description.

P.S.
The ocs is being evaluated in device management commands as well,
Isn't this something you need to attend?

Thanks,
Avri

>         switch (ocs) {
>         case OCS_SUCCESS:
>                 result = ufshcd_get_req_rsp(lrbp->ucd_rsp_ptr);
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index a9b9ace9fc72..e1d09c2c4302 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -541,6 +541,12 @@ enum ufshcd_quirks {
>          * resolution of the values of PRDTO and PRDTL in UTRD as byte.
>          */
>         UFSHCD_QUIRK_PRDT_BYTE_GRAN                     = 1 << 9,
> +
> +       /*
> +        * This quirk needs to be enabled if the host controller reports
> +        * OCS FATAL ERROR with device error through sense data
> +        */
> +       UFSHCD_QUIRK_BROKEN_OCS_FATAL_ERROR             = 1 << 10,
>  };
> 
>  enum ufshcd_caps {
> --
> 2.17.1