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

[Manivannan Sadhasivam <mani@kernel.org>]

On Fri, Dec 08, 2023 at 04:12:44PM +0100, Bean Huo wrote:
> On Fri, 2023-12-08 at 20:20 +0530, Manivannan Sadhasivam wrote:
> > > +        */
> > > +       val = ts64.tv_sec - hba->dev_info.rtc_time_baseline;
> > > +
> > 
> > This logic will work if the host has RTC. But if there is no RTC,
> > then tv_sec
> > will return time elapsed since boot. The spec clearly states that
> > host should
> > use absolute mode if it has RTC and relative otherwise.
> > 
> > Maybe you should add a logic to detect whether RTC is present or not
> > and
> > override the mode in device?
> 
> 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.

- Mani

> 
> Kind regards,
> Bean

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