[PATCH 2/2] drm/etnaviv: print MMU exception cause

[Christian Gmeiner]

Am Fr., 6. Sept. 2019 um 12:55 Uhr schrieb Lucas Stach <l.stach at pengutronix.de>:
>
> On Fr, 2019-09-06 at 12:03 +0200, Christian Gmeiner wrote:
> > Might be useful when debugging MMU exceptions.
> >
> > Signed-off-by: Christian Gmeiner <christian.gmeiner at gmail.com>
> > ---
> >  drivers/gpu/drm/etnaviv/etnaviv_gpu.c | 26
> > ++++++++++++++++++++++++++
> >  1 file changed, 26 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
> > b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
> > index d47d1a8e0219..aa878dd05860 100644
> > --- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
> > +++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
> > @@ -1364,10 +1364,36 @@ static void dump_mmu_fault(struct etnaviv_gpu
> > *gpu)
> >
> >       for (i = 0; i < 4; i++) {
> >               u32 address_reg;
> > +             const char *error;
> >
> >               if (!(status & (VIVS_MMUv2_STATUS_EXCEPTION0__MASK <<
> > (i * 4))))
> >                       continue;
> >
> > +             switch (status) {
> > +             case MMU_EXCEPTION_SLAVE_NOT_PRESENT:
> > +                     error = "slave not present";
> > +                     break;
> > +             case MMU_EXCEPTION_PAGE_NOT_PRESENT:
> > +                     error = "page not present";
> > +                     break;
> > +             case MMU_EXCEPTION_WRITE_VIOLATION:
> > +                     error = "write violation";
> > +                     break;
> > +             case MMU_EXCEPTION_OUT_OF_BOUND:
> > +                     error = "out of bound";
> > +                     break;
> > +             case MMU_EXCEPTION_READ_SECURITY_VIOLATION:
> > +                     error = "read security violation";
> > +                     break;
> > +             case MMU_EXCEPTION_WRITE_SECURITY_VIOLATION:
> > +                     error = "write security violation";
> > +                     break;
> > +             default:
> > +                     error = "unknown state";
> > +                     break;
> > +             }
>
> As the exception status is a nice contiguous set of bits, I think this
> could be simplified into a static array of strings. The error message
> could then just use the bit position to index into the array.
>

I like the idea .. will be done in V2. Thanks for your quick review!

-- 
greets
--
Christian Gmeiner, MSc

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