Re: [PATCH v4 2/3] scsi: ufs: core: Add UFS RTC support

From: Bean Huo
Date: Sun Dec 10 2023 - 14:15:32 EST


On Fri, 2023-12-08 at 23:01 +0530, Manivannan Sadhasivam wrote:
> > >
> > > Thank you for your reviews. I will incorporate the suggested
> > > changes
> > > into the patch, addressing all comments except for the RTC mode
> > > switch.
> > > The proposal is to perform the RTC mode switch during UFS
> > > provisioning,
> > > not at runtime in the UFS online phase. This approach ensures
> > > that the
> > > UFS configuration is populated based on the RTC configuration
> > > established during provisioning. It is advisable not to change
> > > the RTC
> > > mode after provisioning is complete. Additionally, the usage of
> > > tv_sec,
> > > which returns time elapsed since boot, suggests that there is no
> > > issue
> > > with utilizing the RTC in this context.
> >
> > Except that the warning will be issued to users after each 10s for
> > 40 years.
> > Atleast get rid of that.
> >
>
> I tried this series on Qcom RB5 board and found the issue due to the
> usage of
> UFSHCD_QUIRK_REINIT_AFTER_MAX_GEAR_SWITCH flag. When this flag is
> set,
> ufshcd_device_init() will be called twice due to reinit of the
> controller and
> PHY.
>
> Since RTC work is initialized and scheduled from
> ufshcd_device_init(), panic
> happens during second time. Is it possible to move RTC init outside
> of
> ufshcd_device_init(). Maybe you can parse RTC params in
> ufshcd_device_init()
> and initialize the work elsewhere. Or you can cancel the work before
> calling
> ufshcd_device_init() second time.
>
> - Mani


Thank you for your review. I have moved the INIT_DELAYED_WORK(&hba-
>ufs_rtc_update_work, ufshcd_rtc_work) to ufshcd_init() from
ufs_init_rtc(). This modification has been tested on the Qcom platform.
Regarding the warning, instead of removing it entirely, I have switched
it to dev_dbg. This adjustment is made with the consideration that some
form of customer notification is still necessary.

changes as below:


diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 953d50cc4256..cb6b0c286367 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -8205,7 +8205,7 @@ static void ufshcd_update_rtc(struct ufs_hba
*hba)
ktime_get_real_ts64(&ts64);

if (ts64.tv_sec < hba->dev_info.rtc_time_baseline) {
- dev_warn(hba->dev, "%s: Current time precedes previous
setting!\n", __func__);
+ dev_dbg(hba->dev, "%s: Current time precedes previous
setting!\n", __func__);
return;
}
/*
@@ -8270,8 +8270,6 @@ static void ufs_init_rtc(struct ufs_hba *hba, u8
*desc_buf)
* update work, and let user configure by sysfs node according
to specific circumstance.
*/
hba->dev_info.rtc_update_period = 0;
-
- INIT_DELAYED_WORK(&hba->ufs_rtc_update_work, ufshcd_rtc_work);
}

static int ufs_get_device_desc(struct ufs_hba *hba)
@@ -10634,8 +10632,8 @@ int ufshcd_init(struct ufs_hba *hba, void
__iomem *mmio_base, unsigned int irq)
UFS_SLEEP_PWR_MODE,

UIC_LINK_HIBERN8_STATE);

- INIT_DELAYED_WORK(&hba->rpm_dev_flush_recheck_work,
- ufshcd_rpm_dev_flush_recheck_work);
+ INIT_DELAYED_WORK(&hba->rpm_dev_flush_recheck_work,
ufshcd_rpm_dev_flush_recheck_work);
+ INIT_DELAYED_WORK(&hba->ufs_rtc_update_work, ufshcd_rtc_work);

/* Set the default auto-hiberate idle timer value to 150 ms */
if (ufshcd_is_auto_hibern8_supported(hba) && !hba->ahit) {

Kind regards,
Bean