AM3517 Timer busy regression on 6.1.y branch

AM3517 Timer busy regression on 6.1.y branch

[Adam Ford]

Tony et al
,
I am trying to run the 6.1.y branch on an AM3517-EVM.

There are two GPT that throw an error:

 ti-sysc: probe of 48318000.target-module failed with error -16
 ti-sysc: probe of 49032000.target-module failed with error -16

I did some minor investigation and found sysc_check_active_timer() is
returning the busy condition.

I tracked this back a bit further and found that if I revert commit
a12315d6d270  ("bus: ti-sysc: Make omap3 gpt12 quirk handling SoC
specific"), this error condition goes away.

It almost looks to me like sysc_check_active_timer is defaulting to
-EBUSY when the SoC is not 3430, but the sysc_soc_match[] doesn't
appear to match to AM3517.

I think the proper solution is to treat the AM35* as 3430.  Do you
agree with that approach?

If so, I'll submit a patch with a fixes tag. I am also wondering how
far back I should mark the fixes tag.

adam

Re: AM3517 Timer busy regression on 6.1.y branch

[Tony Lindgren]

Hi,

* Adam Ford <aford173@gmail.com> [230905 15:02]:
> Tony et al
> ,
> I am trying to run the 6.1.y branch on an AM3517-EVM.
> 
> There are two GPT that throw an error:
> 
>  ti-sysc: probe of 48318000.target-module failed with error -16
>  ti-sysc: probe of 49032000.target-module failed with error -16

These two timers are in use as clocksource and clockevent reserved
by timer-ti-dm-systimer.

> I did some minor investigation and found sysc_check_active_timer() is
> returning the busy condition.
> 
> I tracked this back a bit further and found that if I revert commit
> a12315d6d270  ("bus: ti-sysc: Make omap3 gpt12 quirk handling SoC
> specific"), this error condition goes away.
> 
> It almost looks to me like sysc_check_active_timer is defaulting to
> -EBUSY when the SoC is not 3430, but the sysc_soc_match[] doesn't
> appear to match to AM3517.
> 
> I think the proper solution is to treat the AM35* as 3430.  Do you
> agree with that approach?
> 
> If so, I'll submit a patch with a fixes tag. I am also wondering how
> far back I should mark the fixes tag.

Yes am3517 is very similar to 3430. Sounds like the patch would
be needed also against the current kernels, right?

Regards,

Tony

Re: AM3517 Timer busy regression on 6.1.y branch

[Adam Ford]

On Wed, Sep 6, 2023 at 9:40 AM Tony Lindgren <tony@atomide.com> wrote:
>
> Hi,
>
> * Adam Ford <aford173@gmail.com> [230905 15:02]:
> > Tony et al
> > ,
> > I am trying to run the 6.1.y branch on an AM3517-EVM.
> >
> > There are two GPT that throw an error:
> >
> >  ti-sysc: probe of 48318000.target-module failed with error -16
> >  ti-sysc: probe of 49032000.target-module failed with error -16
>
> These two timers are in use as clocksource and clockevent reserved
> by timer-ti-dm-systimer.
>
> > I did some minor investigation and found sysc_check_active_timer() is
> > returning the busy condition.
> >
> > I tracked this back a bit further and found that if I revert commit
> > a12315d6d270  ("bus: ti-sysc: Make omap3 gpt12 quirk handling SoC
> > specific"), this error condition goes away.
> >
> > It almost looks to me like sysc_check_active_timer is defaulting to
> > -EBUSY when the SoC is not 3430, but the sysc_soc_match[] doesn't
> > appear to match to AM3517.
> >
> > I think the proper solution is to treat the AM35* as 3430.  Do you
> > agree with that approach?
> >
> > If so, I'll submit a patch with a fixes tag. I am also wondering how
> > far back I should mark the fixes tag.
>
> Yes am3517 is very similar to 3430. Sounds like the patch would
> be needed also against the current kernels, right?

I submitted a patch against the mainline kernel [1] with fixes tags to
hopefully back-port them to 6.1.y.  Any feedback and/or assistance you
can help to move them forward would be appreciated.

adam

[1] - https://patchwork.kernel.org/project/linux-omap/patch/20230906093244.99292-1-aford173@gmail.com/

>
> Regards,
>
> Tony

Re: AM3517 Timer busy regression on 6.1.y branch

[Tony Lindgren]

* Adam Ford <aford173@gmail.com> [230906 15:11]:
> On Wed, Sep 6, 2023 at 9:40 AM Tony Lindgren <tony@atomide.com> wrote:
> >
> > Hi,
> >
> > * Adam Ford <aford173@gmail.com> [230905 15:02]:
> > > Tony et al
> > > ,
> > > I am trying to run the 6.1.y branch on an AM3517-EVM.
> > >
> > > There are two GPT that throw an error:
> > >
> > >  ti-sysc: probe of 48318000.target-module failed with error -16
> > >  ti-sysc: probe of 49032000.target-module failed with error -16
> >
> > These two timers are in use as clocksource and clockevent reserved
> > by timer-ti-dm-systimer.
> >
> > > I did some minor investigation and found sysc_check_active_timer() is
> > > returning the busy condition.
> > >
> > > I tracked this back a bit further and found that if I revert commit
> > > a12315d6d270  ("bus: ti-sysc: Make omap3 gpt12 quirk handling SoC
> > > specific"), this error condition goes away.
> > >
> > > It almost looks to me like sysc_check_active_timer is defaulting to
> > > -EBUSY when the SoC is not 3430, but the sysc_soc_match[] doesn't
> > > appear to match to AM3517.
> > >
> > > I think the proper solution is to treat the AM35* as 3430.  Do you
> > > agree with that approach?
> > >
> > > If so, I'll submit a patch with a fixes tag. I am also wondering how
> > > far back I should mark the fixes tag.
> >
> > Yes am3517 is very similar to 3430. Sounds like the patch would
> > be needed also against the current kernels, right?
> 
> I submitted a patch against the mainline kernel [1] with fixes tags to
> hopefully back-port them to 6.1.y.  Any feedback and/or assistance you
> can help to move them forward would be appreciated.

Thanks v2 looks good to me, will be adding it to fixes and it should get
picked automatically to stable kernels.

Regards,

Tony