Re: [PATCH v1 1/2] scsi: ufs: core: Add UFS RTC support

[Bart Van Assche <bvanassche@acm.org>]

On 11/9/23 04:52, Bean Huo wrote:
> The objective of this patch is to incorporate Real Time Clock (RTC) support in Universal
> Flash Storage (UFS) device. This enhancement is crucial for the internal maintenance
> operations of the UFS device.

That sounds vague. Please explain why a UFS device should know the real
time since other storage devices don't need to know the real time.

> +		dev_info->rtc_time_baseline = mktime64(2010, 1, 1, 0, 0, 0) -
> +								mktime64(1970, 1, 1, 0, 0, 0);

The formatting of the above code is not compliant with the kernel coding
style. Please consider reformatting this patch with e.g.
git clang-format HEAD^.

> +	schedule_delayed_work(&hba->ufs_rtc_delayed_work,
> +							msecs_to_jiffies(UFS_RTC_UPDATE_EVERY_MS));

The formatting of the above code is not compliant with the style guide
either.

> @@ -9746,6 +9834,8 @@ static int __ufshcd_wl_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>   	ret = ufshcd_vops_suspend(hba, pm_op, POST_CHANGE);
>   	if (ret)
>   		goto set_link_active;
> +
> +	cancel_delayed_work(&hba->ufs_rtc_delayed_work);

Why cancel_delayed_work() instead of cancel_delayed_work_sync()?

> @@ -9840,6 +9930,8 @@ static int __ufshcd_wl_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>   		if (ret)
>   			goto set_old_link_state;
>   		ufshcd_set_timestamp_attr(hba);
> +		schedule_delayed_work(&hba->ufs_rtc_delayed_work,
> +							msecs_to_jiffies(UFS_RTC_UPDATE_EVERY_MS));

The name of the constant "UFS_RTC_UPDATE_EVERY_MS" suggests that the
real-time clock is updated 1000 times per second while the comment above
the UFS_RTC_UPDATE_EVERY_MS constant says that it is updated once every
ten seconds. Please choose a better name for UFS_RTC_UPDATE_EVERY_MS,
e.g. UFS_RTC_UPDATE_INTERVAL_MS.

> diff --git a/include/ufs/ufs.h b/include/ufs/ufs.h
> index e77ab1786856..18b39c6b3a97 100644
> --- a/include/ufs/ufs.h
> +++ b/include/ufs/ufs.h
> @@ -14,6 +14,7 @@
>   #include <linux/bitops.h>
>   #include <linux/types.h>
>   #include <uapi/scsi/scsi_bsg_ufs.h>
> +#include <linux/rtc.h>

The include/ufs/ufs.h header file does not depend on anything declared
in <linux/rtc.h> so please move the above include directive into a .c
file.

> +	struct delayed_work ufs_rtc_delayed_work;

Please change the name of this structure member into
ufs_rtc_update_work.

Thanks,

Bart.