Re: [PATCH -next] irq-chip/gic-v3-its: Fixed an issue where the ITS executes the residual commands in the queue again when the ITS wakes up from sleep mode.

[xuqiang (M)]

在 2020/11/10 17:09, xuqiang (M) 写道:
> 在 2020/11/9 18:43, Marc Zyngier 写道:
> > On 2020-11-09 03:05, xuqiang (M) wrote:
> > > 在 2020/11/8 0:54, Marc Zyngier 写道:
> > > > [dropping Jason, whose email address has been bouncing for weeks now]
> > > >
> > > > On 2020-11-07 10:42, Xu Qiang wrote:
> > > > > On my platform, ITS_FLAGS_SAVE_SUSPEND_STATE is not set,thus do 
> > > > > nothing
> > > >
> > > > Which platform?
> > > Hisi Ascend platform
> > > > > in its suspend and resuse function.On the other hand,firmware stores
> > > > > GITS_CTRL,GITS_CBASER,GITS_CWRITER and GITS_BASER<n> in the suspend,
> > > > > and restores these registers in the resume. As a result, the ITS 
> > > > > executes
> > > > > the residual commands in the queue.
> > > >
> > > > Which firmware are you using? I just had a look at the trusted 
> > > > firmware source
> > > > code, and while it definitely does something that *looks* like what 
> > > > you are
> > > > describing, it doesn't re-enable the ITS on resume.
> > > >
> > > > So what are you running?
> > >
> > > I am using ATF. Since ITS_FLAGS_SAVE_SUSPEND_STATE is not set,ITS
> > > driver of OS will
> > >
> > > not re-enable ITS in th resume. To make ITS work properly, we changed
> > > the ATF code
> > >
> > > to re-enable ITS on resume.
> >
> > I don't think the words "work properly" apply here.
> >
> > The kernel didn't do what you wanted, so instead of fixing the 
> > kernel, you
> > introduced a bug that results in memory corruption from the firmware.
> >
> > What are you plans to fix your firmware? Because from an upstream ATF
> > compatibility PoV, all there is to do is to fixup the command queue and
> > enable the ITS.
> >
> >         M.
>
>
> I'm sorry I didn't make it clear how to do this. I'm going to reset 
> commit
>
> which re-enable ITS  on the ATF, and drop the checks for 
> ITS_FLAGS_SAVE_SUSPEND_STATE
>
> in the OS.
>
> In other words, the ATF does not re-enable ITS, and OS itself 
> re-enables ITS when it resumes.
>
> To do this, I have to remove the check of ITS_FLAGS_SAVE_SUSPEND_STATE 
> because it is not set.
>
>
> Thanks
>
>         Xu.
Hi Marc

    I have been waiting for your reply. Are there any questions about 
this modification plan?

Thanks

        Xu.