[Mesa-dev] [PATCH] winsys/radeon: fix a wrong NUM_TILE_PIPES value from the kernel

[Marek Olšák]

On Tue, Feb 9, 2016 at 6:17 PM, Alexandre Demers
<alexandre.f.demers at gmail.com> wrote:
>> +            /* The kernel returns 12 for some cards for an unknown
>> reason.
>> +             * I thought this was supposed to be a power of two.
>> +             */
>> +            if (ws->gen == DRV_SI && ws->info.num_tile_pipes == 12)
>> +                ws->info.num_tile_pipes = 8;
>> +
>
> I may be late in the conversation, but shouldn't we have a look at why the
> value reported by the kernel is wrong for "some" cards? Which ones and why
> should be identified. It seems to be limited to Southern Islands as far as
> we know for now, which limits the scope for now.
>
> Also, about the patch itself, even if only some cards were reported to be
> problematic, why would we limit it to "ws->gen == DRV_SI"? Any cards
> reporting a wrong value should be treated the same way by mapping its value
> from 12 to 8, no?

No. Only one card is affected (Tahiti or Pitcairn, I don't remember
which one). No other card reports 12.

There is no point in looking into why the value is wrong and I haven't
been able to find where the value had come from. It's part of the
kernel ABI now anyway. Userspace won't use it anymore.

Marek