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

[Bean Huo]

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