Re: [PATCH v5 1/7] scsi: ufs: Add "wb_on" sysfs node to control WB on/off

Bean Huo
2020-12-22T21:09:41Z

On Tue, 2020-12-22 at 21:50 +0100, Bean Huo wrote:
> >
> > May this operation race with UFS shutdown flow?
> >
> > To be more clear, ufshcd_wb_ctrl() here may be executed after host
> > clock
> > is disabled by shutdown flow?
> >
> > If yes, we need to avoid it.
> >
> > Thanks,
> > Stanley Chu
>
> Yes, it is quite possible, but who will mess up this on purpose?
>
> ok, to counterbalance our concerns, I can add checkup:
>
>
> /* UFS device & link must be active before we change WB status */
> if (!ufshcd_is_ufs_dev_active(hba) || !ufshcd_is_link_active(hba))
> return -EINVAL;
>
>
> how do you think about?
>
> Bean

seems there are only auto_hibern8 and wb will issue command to UFS
device. if you think auto_hibern8 also needs this protection.

I will add in the next version patch, otherwise, just add this checkup
in the WB.

Look forward to your feedback!

Thanks,
Bean