On Aug 21, 2015 3:10 PM, "Yaniv Gardi" <ygardi@xxxxxxxxxxxxxx> wrote:
>
> Sometimes queries from the device might return a failure so it is
> recommended to retry sending the query, before giving up.
> This change adds a wrapper to retry sending a query attribute,
> in cases where we need to wait longer, before we continue,
> or before reporting a failure.
Why not just always retry? Are there cases where retrying would be a problem?
>
> Signed-off-by: Yaniv Gardi <ygardi@xxxxxxxxxxxxxx>
>
> ---
> drivers/scsi/ufs/ufshcd.c | 51 ++++++++++++++++++++++++++++++++++++++++-------
> 1 file changed, 44 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 876148b..bfef67d 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -1827,6 +1827,43 @@ out:
> }
>
> /**
> + * ufshcd_query_attr_retry() - API function for sending query
> + * attribute with retries
> + * @hba: per-adapter instance
> + * @opcode: attribute opcode
> + * @idn: attribute idn to access
> + * @index: index field
> + * @selector: selector field
> + * @attr_val: the attribute value after the query request
> + * completes
> + *
> + * Returns 0 for success, non-zero in case of failure
> +*/
> +static int ufshcd_query_attr_retry(struct ufs_hba *hba,
> + enum query_opcode opcode, enum attr_idn idn, u8 index, u8 selector,
> + u32 *attr_val)
> +{
> + int ret = 0;
> + u32 retries;
> +
> + for (retries = QUERY_REQ_RETRIES; retries > 0; retries--) {
> + ret = ufshcd_query_attr(hba, opcode, idn, index,
> + selector, attr_val);
> + if (ret)
> + dev_dbg(hba->dev, "%s: failed with error %d, retries %d\n",
> + __func__, ret, retries);
> + else
> + break;
> + }
> +
> + if (ret)
> + dev_err(hba->dev,
> + "%s: query attribute, idn %d, failed with error %d after %d retires\n",
> + __func__, idn, ret, retries);
The retry count will be wrong here.
> + return ret;
> +}
> +
> +/**
> * ufshcd_query_descriptor - API function for sending descriptor requests
> * hba: per-adapter instance
> * opcode: attribute opcode
> @@ -3407,7 +3444,7 @@ static int ufshcd_disable_ee(struct ufs_hba *hba, u16 mask)
>
> val = hba->ee_ctrl_mask & ~mask;
> val &= 0xFFFF; /* 2 bytes */
> - err = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
> + err = ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
> QUERY_ATTR_IDN_EE_CONTROL, 0, 0, &val);
> if (!err)
> hba->ee_ctrl_mask &= ~mask;
> @@ -3435,7 +3472,7 @@ static int ufshcd_enable_ee(struct ufs_hba *hba, u16 mask)
>
> val = hba->ee_ctrl_mask | mask;
> val &= 0xFFFF; /* 2 bytes */
> - err = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
> + err = ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
> QUERY_ATTR_IDN_EE_CONTROL, 0, 0, &val);
> if (!err)
> hba->ee_ctrl_mask |= mask;
> @@ -3541,7 +3578,7 @@ static void ufshcd_force_reset_auto_bkops(struct ufs_hba *hba)
>
> static inline int ufshcd_get_bkops_status(struct ufs_hba *hba, u32 *status)
> {
> - return ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,
> + return ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_READ_ATTR,
> QUERY_ATTR_IDN_BKOPS_STATUS, 0, 0, status);
> }
>
> @@ -3604,7 +3641,7 @@ static int ufshcd_urgent_bkops(struct ufs_hba *hba)
>
> static inline int ufshcd_get_ee_status(struct ufs_hba *hba, u32 *status)
> {
> - return ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,
> + return ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_READ_ATTR,
> QUERY_ATTR_IDN_EE_STATUS, 0, 0, status);
> }
>
> @@ -4360,9 +4397,9 @@ static void ufshcd_init_icc_levels(struct ufs_hba *hba)
> dev_dbg(hba->dev, "%s: setting icc_level 0x%x",
> __func__, hba->init_prefetch_data.icc_level);
>
> - ret = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
> - QUERY_ATTR_IDN_ACTIVE_ICC_LVL, 0, 0,
> - &hba->init_prefetch_data.icc_level);
> + ret = ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
> + QUERY_ATTR_IDN_ACTIVE_ICC_LVL, 0, 0,
> + &hba->init_prefetch_data.icc_level);
>
> if (ret)
> dev_err(hba->dev,
> --
> 1.8.5.2
>
> --
> QUALCOMM ISRAEL, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
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