Re: [PATCH] drm/msm/adreno: Make adreno quirks not overwrite each other

From: Rob Clark
Date: Sun Jan 01 2023 - 17:18:31 EST


On Thu, Dec 29, 2022 at 2:47 AM Marijn Suijten
<marijn.suijten@xxxxxxxxxxxxxx> wrote:
>
> On 2022-12-29 11:18:45, Konrad Dybcio wrote:
> > So far the adreno quirks have all been assigned with an OR operator,
> > which is problematic, because they were assigned consecutive integer
> > values, which makes checking them with an AND operator kind of no bueno..
> >
> > Switch to using BIT(n) so that only the quirks that the programmer chose
> > are taken into account when evaluating info->quirks & ADRENO_QUIRK_...
> >
> > Fixes: b5f103ab98c7 ("drm/msm: gpu: Add A5XX target support")
> > Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>
>
> Nice catch!
>
> Reviewed-by: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx>
>
> Not sure if it's the right Fixes commit though, as it would have worked
> when ADRENO_QUIRK_LMLOADKILL_DISABLE was added with constant 4 instead
> of 3 in 370063ee427a ("drm/msm/adreno: Add A540 support"), but then
> using bitflags in an enum value type is invalid anyway, AFAIK.

It isn't a thing that c++ like so much, but for c code, gdb will
decode enum bitfields in a sensible way (IIRC). Also, maybe it
doesn't matter at this point, but it would conflict for stable
backports prior to adding LMLOADKILL_DISABLE.

with the fixes msg corrected,

Reviewed-by: Rob Clark <robdclark@xxxxxxxxx>

> - Marijn
>
> > ---
> > drivers/gpu/drm/msm/adreno/adreno_gpu.h | 10 ++++------
> > 1 file changed, 4 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.h b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> > index c85857c0a228..5eb254c9832a 100644
> > --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> > +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> > @@ -29,11 +29,9 @@ enum {
> > ADRENO_FW_MAX,
> > };
> >
> > -enum adreno_quirks {
> > - ADRENO_QUIRK_TWO_PASS_USE_WFI = 1,
> > - ADRENO_QUIRK_FAULT_DETECT_MASK = 2,
> > - ADRENO_QUIRK_LMLOADKILL_DISABLE = 3,
> > -};
> > +#define ADRENO_QUIRK_TWO_PASS_USE_WFI BIT(0)
> > +#define ADRENO_QUIRK_FAULT_DETECT_MASK BIT(1)
> > +#define ADRENO_QUIRK_LMLOADKILL_DISABLE BIT(2)
> >
> > struct adreno_rev {
> > uint8_t core;
> > @@ -65,7 +63,7 @@ struct adreno_info {
> > const char *name;
> > const char *fw[ADRENO_FW_MAX];
> > uint32_t gmem;
> > - enum adreno_quirks quirks;
> > + u64 quirks;
> > struct msm_gpu *(*init)(struct drm_device *dev);
> > const char *zapfw;
> > u32 inactive_period;
> > --
> > 2.39.0
> >