[PATCH 2/2] drm: etnaviv: add further minor features and varyings count

[Lucas Stach]

Am Mittwoch, den 20.01.2016, 19:01 +0100 schrieb Christian Gmeiner:
> Hi Russell
> 
> 2016-01-19 11:21 GMT+01:00 Russell King - ARM Linux <linux at arm.linux.org.uk>:
> > On Tue, Jan 19, 2016 at 11:09:57AM +0100, Christian Gmeiner wrote:
> >> Hi Russell,
> >>
> >> 2016-01-19 10:18 GMT+01:00 Russell King <rmk+kernel at arm.linux.org.uk>:
> >> > +       /*
> >> > +        * For some cores, two varyings are consumed for position, so the
> >> > +        * maximum varying count needs to be reduced by one.
> >> > +        */
> >> > +       if ((gpu->identity.model == chipModel_GC2000 &&
> >> > +            gpu->identity.revision == 0x5108) ||
> >> > +           (gpu->identity.model == chipModel_GC880 &&
> >> > +            gpu->identity.revision == 0x5106))
> >> > +               gpu->identity.varyings_count -= 1;
> >>
> >> Should we not include the whole list of GPU cores with that special handling?
> >> See: https://github.com/Freescale/kernel-module-imx-gpu-viv/blob/master/kernel-module-imx-gpu-viv-src/hal/kernel/arch/gc_hal_kernel_hardware.c#L592
> >
> > I was debating about that - but I think we need to come up with a better
> > way to do this sort of thing.  At the very least, I've been wondering
> > whether a macro such as:
> >
> > #define etnaviv_model_rev(gpu, mod, rev) \
> >         ((gpu)->identity.model == chipModel_##mod && \
> >          (gpu)->identity.revision == rev))
> >
> > would help make some of this code more readable.
> >
> 
> Yep that makes the code more readable.
> 
This macro seems like a very reasonable simplification.

> > The other thing I've been wondering is whether a table looked up by GPU
> > model ID and/or revision ID quirks would simplify this.  However, the
> > downside with the tabular approach is that it becomes harder to compare
> > what we have against the galcore sources.
> >
> 
> The table driven approach could be a little heavy for the number of
> quirks we have
> currently. Maybe Lucas has an opinion about that?
> 
I don't think that having a quirk table is useful for the current number
of quirks and from what I have seen from the Vivante kernel sources.

Regards,
Lucas 

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