RE: [PATCH v2 4/4] scsi: ufs: Add history of fatal events

Avri Altman
2019-07-10T08:04:17Z

Hi Stanley,

>
> Currently only "interrupt-based" errors have their own history,
> however there are "non-interrupt-based" errors which may be
> fatal also needing history to improve debugging or help know
> the health status of UFS devices.
>
> For example,
> - Link startup fail
> - Suspend fail
> - Resume fail
> - Task or request abort event
>
> This patch tries to add those failed events by existed UFS error
> history mechanism.
>
> Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
> ---
> drivers/scsi/ufs/ufshcd.c | 36 +++++++++++++++++++++++++++---------
> drivers/scsi/ufs/ufshcd.h | 10 ++++++++++
> 2 files changed, 37 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index a46c3d2b2ea3..969128a731e1 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -432,6 +432,14 @@ static void ufshcd_print_host_regs(struct ufs_hba
> *hba)
> ufshcd_print_err_hist(hba, &hba->ufs_stats.fatal_err, "fatal_err");
> ufshcd_print_err_hist(hba, &hba->ufs_stats.auto_hibern8_err,
> "auto_hibern8_err");
> + ufshcd_print_err_hist(hba, &hba->ufs_stats.task_abort_err,
> + "task_abort");
> + ufshcd_print_err_hist(hba, &hba->ufs_stats.link_startup_err,
> + "link_startup_fail");
> + ufshcd_print_err_hist(hba, &hba->ufs_stats.suspend_err,
> + "suspend_fail");
> + ufshcd_print_err_hist(hba, &hba->ufs_stats.resume_err,
> + "resume_fail");
>
> ufshcd_print_clk_freqs(hba);
>
> @@ -4329,6 +4337,14 @@ static inline int
> ufshcd_disable_device_tx_lcc(struct ufs_hba *hba)
> return ufshcd_disable_tx_lcc(hba, true);
> }
>
> +static void ufshcd_update_reg_hist(struct ufs_err_reg_hist *reg_hist,
> + u32 reg)
> +{
> + reg_hist->reg[reg_hist->pos] = reg;
> + reg_hist->tstamp[reg_hist->pos] = ktime_get();
> + reg_hist->pos = (reg_hist->pos + 1) % UFS_ERR_REG_HIST_LENGTH;
> +}
> +
> /**
> * ufshcd_link_startup - Initialize unipro link startup
> * @hba: per adapter instance
> @@ -4356,6 +4372,8 @@ static int ufshcd_link_startup(struct ufs_hba
> *hba)
>
> /* check if device is detected by inter-connect layer */
> if (!ret && !ufshcd_is_device_present(hba)) {
> + ufshcd_update_reg_hist(&hba-
> >ufs_stats.link_startup_err,
> + 0);
> dev_err(hba->dev, "%s: Device not present\n",
> __func__);
> ret = -ENXIO;
> goto out;
> @@ -4366,8 +4384,11 @@ static int ufshcd_link_startup(struct ufs_hba
> *hba)
> * but we can't be sure if the link is up until link startup
> * succeeds. So reset the local Uni-Pro and try again.
> */
> - if (ret && ufshcd_hba_enable(hba))
> + if (ret && ufshcd_hba_enable(hba)) {
> + ufshcd_update_reg_hist(&hba-
> >ufs_stats.link_startup_err,
> + (u32)ret);
> goto out;
> + }
> } while (ret && retries--);
>
> if (ret)
Here also link startup fails...

> @@ -5350,14 +5371,6 @@ static void ufshcd_err_handler(struct
> work_struct *work)
> pm_runtime_put_sync(hba->dev);
> }
>
> -static void ufshcd_update_reg_hist(struct ufs_err_reg_hist *reg_hist,
> - u32 reg)
> -{
> - reg_hist->reg[reg_hist->pos] = reg;
> - reg_hist->tstamp[reg_hist->pos] = ktime_get();
> - reg_hist->pos = (reg_hist->pos + 1) % UFS_ERR_REG_HIST_LENGTH;
> -}
> -
> /**
> * ufshcd_update_uic_error - check and set fatal UIC error flags.
> * @hba: per-adapter instance
> @@ -6043,6 +6056,7 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
> */
> scsi_print_command(hba->lrb[tag].cmd);
> if (!hba->req_abort_count) {
> + ufshcd_update_reg_hist(&hba->ufs_stats.task_abort_err,
> 0);
Here you are collecting abort events statistics, not abort errors.
If this is what you meant, then it's not task_abort_err, but task_abort.
And if indeed you are tracking task aborts, maybe add lun resets as well?

> ufshcd_print_host_regs(hba);
> ufshcd_print_host_state(hba);
> ufshcd_print_pwr_info(hba);
> @@ -7819,6 +7833,8 @@ static int ufshcd_suspend(struct ufs_hba *hba,
> enum ufs_pm_op pm_op)
> ufshcd_release(hba);
> out:
> hba->pm_op_in_progress = 0;
> + if (ret)
> + ufshcd_update_reg_hist(&hba->ufs_stats.suspend_err,
> (u32)ret);
> return ret;
> }
>
> @@ -7921,6 +7937,8 @@ static int ufshcd_resume(struct ufs_hba *hba,
> enum ufs_pm_op pm_op)
> ufshcd_setup_clocks(hba, false);
> out:
> hba->pm_op_in_progress = 0;
> + if (ret)
> + ufshcd_update_reg_hist(&hba->ufs_stats.resume_err,
> (u32)ret);
> return ret;
> }
>
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index c6ec5c749ceb..f9f109da7f18 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -438,6 +438,10 @@ struct ufs_err_reg_hist {
> * @dme_err: tracks dme errors
> * @fatal_err: tracks fatal errors
> * @auto_hibern8_err: tracks auto-hibernate errors
> + * @tsk_abort_err: tracks task abort events
> + * @linkup_err: tracks link-startup fail events
> + * @suspend_err: tracks suspend fail events
> + * @resume_err: tracks resume fail events
> */
> struct ufs_stats {
> u32 hibern8_exit_cnt;
> @@ -453,6 +457,12 @@ struct ufs_stats {
> /* fatal errors */
> struct ufs_err_reg_hist fatal_err;
> struct ufs_err_reg_hist auto_hibern8_err;
> +
> + /* fatal events */
Maybe move here fatal_err as well?

> + struct ufs_err_reg_hist task_abort_err;
> + struct ufs_err_reg_hist link_startup_err;
> + struct ufs_err_reg_hist suspend_err;
> + struct ufs_err_reg_hist resume_err;
> };
>
> /**
> --
> 2.18.0

Thanks,
Avri