Re: [PATCH 02/10] scsi: ufs: add quirk to contain unconformable utrd field

[amit daniel kachhap]

Few minor comments below,

On Fri, Aug 21, 2015 at 2:57 PM, Alim Akhtar <alim.akhtar@xxxxxxxxxxx> wrote:
> From: Seungwon Jeon <tgih.jun@xxxxxxxxxxx>
>
> UTRD(UTP Transfer Request Descriptor)'s field such as offset/length,
> especially response's has DWORD expression. This quirk can be specified
> for host controller not to conform standard.
>
> Signed-off-by: Seungwon Jeon <tgih.jun@xxxxxxxxxxx>
> Signed-off-by: Alim Akhtar <alim.akhtar@xxxxxxxxxxx>
> ---
>  drivers/scsi/ufs/ufshcd.c |   28 +++++++++++++++++++++-------
>  drivers/scsi/ufs/ufshcd.h |    7 +++++++
>  2 files changed, 28 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index b0ade73..f882bf0 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -1009,7 +1009,7 @@ ufshcd_send_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
>   *
>   * Returns 0 in case of success, non-zero value in case of failure
>   */
> -static int ufshcd_map_sg(struct ufshcd_lrb *lrbp)
> +static int ufshcd_map_sg(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
>  {
>         struct ufshcd_sg_entry *prd_table;
>         struct scatterlist *sg;
> @@ -1023,8 +1023,13 @@ static int ufshcd_map_sg(struct ufshcd_lrb *lrbp)
>                 return sg_segments;
>
>         if (sg_segments) {
> -               lrbp->utr_descriptor_ptr->prd_table_length =
> -                                       cpu_to_le16((u16) (sg_segments));
> +               if (hba->quirks & UFSHCI_QUIRK_BROKEN_UTRD)
> +                       lrbp->utr_descriptor_ptr->prd_table_length =
> +                               cpu_to_le16((u16)(sg_segments *
> +                                       sizeof(struct ufshcd_sg_entry)));
> +               else
> +                       lrbp->utr_descriptor_ptr->prd_table_length =
> +                               cpu_to_le16((u16) (sg_segments));
>
>                 prd_table = (struct ufshcd_sg_entry *)lrbp->ucd_prdt_ptr;
>
> @@ -1347,7 +1352,7 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
>
>         /* form UPIU before issuing the command */
>         ufshcd_compose_upiu(hba, lrbp);
> -       err = ufshcd_map_sg(lrbp);
> +       err = ufshcd_map_sg(hba, lrbp);
>         if (err) {
>                 lrbp->cmd = NULL;
>                 clear_bit_unlock(tag, &hba->lrb_in_use);
> @@ -2035,12 +2040,21 @@ static void ufshcd_host_memory_configure(struct ufs_hba *hba)
>                                 cpu_to_le32(upper_32_bits(cmd_desc_element_addr));
>
>                 /* Response upiu and prdt offset should be in double words */
This comment can be moved below for the else case.
> -               utrdlp[i].response_upiu_offset =
> +               if (hba->quirks & UFSHCI_QUIRK_BROKEN_UTRD) {
> +                       utrdlp[i].response_upiu_offset =
> +                               cpu_to_le16(response_offset);
> +                       utrdlp[i].prd_table_offset =
> +                               cpu_to_le16(prdt_offset);
> +                       utrdlp[i].response_upiu_length =
> +                               cpu_to_le16(ALIGNED_UPIU_SIZE);
> +               } else {
> +                       utrdlp[i].response_upiu_offset =
>                                 cpu_to_le16((response_offset >> 2));
> -               utrdlp[i].prd_table_offset =
> +                       utrdlp[i].prd_table_offset =
>                                 cpu_to_le16((prdt_offset >> 2));
> -               utrdlp[i].response_upiu_length =
> +                       utrdlp[i].response_upiu_length =
>                                 cpu_to_le16(ALIGNED_UPIU_SIZE >> 2);
> +               }
>
>                 hba->lrb[i].utr_descriptor_ptr = (utrdlp + i);
>                 hba->lrb[i].ucd_req_ptr =
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index c40a0e7..1fa5ac1 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -459,6 +459,13 @@ struct ufs_hba {
>          */
>         #define UFSHCD_QUIRK_BROKEN_UFS_HCI_VERSION             UFS_BIT(5)
>
> +       /*
> +        * This quirk needs to be enabled if host controller doesn't conform
> +        * with UTRD. Some fields such as offset/length might not be in double word,
> +        * but in byte.
> +        */
> +       #define UFSHCI_QUIRK_BROKEN_UTRD                        UFS_BIT(6)
This macro name may be given more meaningful name such as
UFSHCI_QUIRK_BYTE_ALIGN_UTRD or something similar.
> +
>         unsigned int quirks;    /* Deviations from standard UFSHCI spec. */
>
>         wait_queue_head_t tm_wq;
> --
> 1.7.10.4
>
> --
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