Re: [PATCH v5 09/15] scsi: ufs: add retries for hibern8 enter

["Gilad Broner" <gbroner@codeaurora.org>]

Reviewed-by: Gilad Broner <gbroner@codeaurora.org>

> If hibern8 enter command fails then UFS link state may be unknown which
> may result into timeout of all the commands issued after failure.
>
> This change does 2 things (for pre-defined number of retry counts) after
> hibern8 enter failure:
> 1. Recovers the UFS link to active state
> 2. If link is recovered to active state, tries to put the UFS link in
>    hibern8 enter again until retry count expires.
>
> Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
> Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
>
> ---
>  drivers/scsi/ufs/ufshcd.c | 26 ++++++++++++++++++++++++--
>  1 file changed, 24 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 5005d12..ed134d6 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -76,6 +76,9 @@
>  /* maximum number of link-startup retries */
>  #define DME_LINKSTARTUP_RETRIES 3
>
> +/* Maximum retries for Hibern8 enter */
> +#define UIC_HIBERN8_ENTER_RETRIES 3
> +
>  /* maximum number of reset retries before giving up */
>  #define MAX_HOST_RESET_RETRIES 5
>
> @@ -2390,13 +2393,32 @@ out:
>  	return ret;
>  }
>
> -static int ufshcd_uic_hibern8_enter(struct ufs_hba *hba)
> +static int __ufshcd_uic_hibern8_enter(struct ufs_hba *hba)
>  {
> +	int ret;
>  	struct uic_command uic_cmd = {0};
>
>  	uic_cmd.command = UIC_CMD_DME_HIBER_ENTER;
> +	ret = ufshcd_uic_pwr_ctrl(hba, &uic_cmd);
> +
> +	if (ret)
> +		dev_err(hba->dev, "%s: hibern8 enter failed. ret = %d\n",
> +			__func__, ret);
> +
> +	return ret;
> +}
> +
> +static int ufshcd_uic_hibern8_enter(struct ufs_hba *hba)
> +{
> +	int ret = 0, retries;
>
> -	return ufshcd_uic_pwr_ctrl(hba, &uic_cmd);
> +	for (retries = UIC_HIBERN8_ENTER_RETRIES; retries > 0; retries--) {
> +		ret = __ufshcd_uic_hibern8_enter(hba);
> +		if (!ret || ret == -ENOLINK)
> +			goto out;
> +	}
> +out:
> +	return ret;
>  }
>
>  static int ufshcd_uic_hibern8_exit(struct ufs_hba *hba)
> --
> 1.8.5.2
>
> --
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