Re: [PATCH 2/2] scsi: ufs: Protect PM ops and err_handler from user access through sysfs

[Can Guo]

On 2021-01-11 18:04, Bean Huo wrote:
> On Mon, 2021-01-11 at 17:22 +0800, Can Guo wrote:
> > > > meaning you are tring to access a register when clocks are
> > > > disabled.
> > > > This
> > > > leads to system CRASH.
> > > >
> > >
> > > OK, let it simple, share this kind of crash log becuase of access
> > > sysfs
> > > node in the shutdown flow.
> > >
> > >
> > > > [2] OCP is over current protection. While UFS shutting down, you
> > > > may
> > > > have put UFS regulators to LPM. After that, if you are still
> > > > trying
> > > > to
> > > > talk to UFS, OCP can happen on VCCQ/VCCQ2. This leads to system
> > > > CRASH
> > > > too.
> > >
> > > the same as above, share the crash log.
> > >
> >
> > If you have hand-on experiences on NoC and/or OCP issues, you won't
> > ask
> > for the crash log. The tricky parts about critial NoC and OCP issues
> > is
>
> OK, interesting. would you tell me which register access node in ufs-
> sysfs.c can trigger this crash? let me verify your statement.

I believe I have explained enough to prove we need this change.

If you are really interested in NoC and OCP, feel free to ping me
on teams, I will show you how to trigger one and what is it like
on my setup.

Can Guo.

> Bean
>
> >