Re: [PATCH v3 09/15] scsi: ufs: add retries for hibern8 enter

From: Akinobu Mita
Date: Wed Oct 21 2015 - 10:54:24 EST


2015-09-02 19:13 GMT+09:00 Yaniv Gardi <ygardi@xxxxxxxxxxxxxx>:
> 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@xxxxxxxxxxxxxx>
> Signed-off-by: Yaniv Gardi <ygardi@xxxxxxxxxxxxxx>
>
> ---
> 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 8d5bdf0..5800b08 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -75,6 +75,9 @@
> /* 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
>
> @@ -2389,13 +2392,32 @@ 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",
> + __func__, ret);

This format string is not terminated with '\n'.
(I found several same issues in ufshcd.c)

> +
> + return ret;
> +}
> +
> +static int ufshcd_uic_hibern8_enter(struct ufs_hba *hba)
> +{
> + int ret = 0, retries;
>

'ret' will soon be initialized in the loop anyway, so it is unnecessary
to initialized here.

> - 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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