Re: [PATCH v20 1/2] scsi: ufs: Enable power management for wlun

[Asutosh Das (asd)]

On 4/19/2021 11:37 AM, Adrian Hunter wrote:
> On 16/04/21 10:49 pm, Asutosh Das wrote:
> > Co-developed-by: Can Guo <cang@xxxxxxxxxxxxxx>
> > Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
> > Signed-off-by: Asutosh Das <asutoshd@xxxxxxxxxxxxxx>
> > ---
>
> I came across 3 issues while testing.  See comments below.
Hi Adrian
Thanks for the comments.
> <SNIP>
>
> > @@ -5794,7 +5839,7 @@ static void ufshcd_err_handling_unprepare(struct ufs_hba *hba)
> >   	if (ufshcd_is_clkscaling_supported(hba))
> >   		ufshcd_clk_scaling_suspend(hba, false);
> >   	ufshcd_clear_ua_wluns(hba);
>
> ufshcd_clear_ua_wluns() deadlocks trying to clear UFS_UPIU_RPMB_WLUN
> if sdev_rpmb is suspended and sdev_ufs_device is suspending.
> e.g. ufshcd_wl_suspend() is waiting on host_sem while ufshcd_err_handler()
> is running, at which point sdev_rpmb has already suspended.
Umm, I didn't understand this deadlock.
When you say, sdev_rpmb is suspended, does it mean runtime_suspended?
sdev_ufs_device is suspending - this can't be runtime_suspending, while 
ufshcd_err_handling_unprepare is running.

If you've a call-stack of this deadlock, please can you share it with 
me. I'll also try to reproduce this.

I'll address the other comments in the next version.


Thank you!

> > -	pm_runtime_put(hba->dev);
> > +	ufshcd_rpm_put(hba);
> >   }
>
> <SNIP>
>
> > +void ufshcd_resume_complete(struct device *dev)
> > +{

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