Re: [PATCH 04/10] scsi: ufs: add quirk not to allow reset of interrupt aggregation

[amit daniel kachhap]

Few comments below,

On Fri, Aug 21, 2015 at 2:57 PM, Alim Akhtar <alim.akhtar@xxxxxxxxxxx> wrote:
> From: Seungwon Jeon <tgih.jun@xxxxxxxxxxx>
>
> Some host controller supports interrupt aggregation, but doesn't
> allow to reset counter and timer by s/w.
>
> Signed-off-by: Seungwon Jeon <tgih.jun@xxxxxxxxxxx>
> Signed-off-by: Alim Akhtar <alim.akhtar@xxxxxxxxxxx>
> ---
>  drivers/scsi/ufs/ufshcd.c |    3 ++-
>  drivers/scsi/ufs/ufshcd.h |    6 ++++++
>  2 files changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index b441a39..35380aa 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -3204,7 +3204,8 @@ static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
>          * false interrupt if device completes another request after resetting
>          * aggregation and before reading the DB.
>          */
> -       if (ufshcd_is_intr_aggr_allowed(hba))
> +       if (ufshcd_is_intr_aggr_allowed(hba) &&
> +           !(hba->quirks & UFSHCI_QUIRK_BROKEN_RESET_INTR_AGGR))
How about to rename this quirk as UFSHCI_QUIRK_SKIP_RESET_INTR_AGGR as
there are some drawbacks about the existing method also as per the
comments above. Or this can be also put as opts instead as quirk.
>                 ufshcd_reset_intr_aggr(hba);
>
>         tr_doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index 24245c9..7986a54 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -471,6 +471,12 @@ struct ufs_hba {
>          */
>         #define UFSHCI_QUIRK_BROKEN_REQ_LIST_CLR                UFS_BIT(7)
>
> +       /*
> +        * This quirk needs to be enabled if host controller doesn't allow
> +        * that the interrupt aggregation timer and counter are reset by s/w.
> +        */
> +       #define UFSHCI_QUIRK_BROKEN_RESET_INTR_AGGR             UFS_BIT(8)
> +
>         unsigned int quirks;    /* Deviations from standard UFSHCI spec. */
>
>         wait_queue_head_t tm_wq;
> --
> 1.7.10.4
>
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