[Mesa-dev] [PATCH] r300g: only allow byteswapped formats on big endian

[Marek Olšák]

I've changed my mind. The patch can be merged if nobody disagrees.

Marek

On Feb 13, 2017 2:10 PM, "Marek Olšák" <maraeo at gmail.com> wrote:

> I'd like some evidence that the bug is caused by r300g and not some common
> code.
>
> Marek
>
> On Feb 13, 2017 12:10 PM, "Grazvydas Ignotas" <notasas at gmail.com> wrote:
>
>> On Mon, Feb 13, 2017 at 10:22 AM, Michel Dänzer <michel at daenzer.net>
>> wrote:
>> > On 13/02/17 05:17 PM, Michel Dänzer wrote:
>> >> On 11/02/17 08:01 AM, Grazvydas Ignotas wrote:
>> >>> They cause regressions on little endian.
>> >>>
>> >>> Fixes: 172bfdaa9e ("r300g: add support for PIPE_FORMAT_x8R8G8B8_*")
>> >>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98869
>> >>> Signed-off-by: Grazvydas Ignotas <notasas at gmail.com>
>> >>> ---
>> >>> no commit access
>> >>>
>> >>>  src/gallium/drivers/r300/r300_texture.c | 5 +++++
>> >>>  1 file changed, 5 insertions(+)
>> >>>
>> >>> diff --git a/src/gallium/drivers/r300/r300_texture.c
>> b/src/gallium/drivers/r300/r300_texture.c
>> >>> index fbac07a..929c3fe 100644
>> >>> --- a/src/gallium/drivers/r300/r300_texture.c
>> >>> +++ b/src/gallium/drivers/r300/r300_texture.c
>> >>> @@ -47,6 +47,11 @@
>> >>>   */
>> >>>  static enum pipe_format r300_unbyteswap_array_format(enum
>> pipe_format format)
>> >>>  {
>> >>> +    /* FIXME: Disabled on little endian because of a reported
>> regression:
>> >>> +     * https://bugs.freedesktop.org/show_bug.cgi?id=98869 */
>> >>> +    if (PIPE_ENDIAN_NATIVE != PIPE_ENDIAN_BIG)
>> >>> +        return format;
>> >>
>> >> Is there any reason to believe that whatever issue this avoids couldn't
>> >> happen on big endian hosts as well?
>>
>> I don't know...
>>
>> > More to the point, this seems to disable part of the logic needed for
>> > supporting PIPE_FORMAT_x8R8G8B8_* on little endian, but leaves those
>> > formats advertised as supported.
>>
>> Well it just reverts to an earlier working state before Marek's patch
>> (172bfdaa9e) tor LE.
>> The patch in question which added support for those formats hasn't
>> done anything specific related to advertising them, and
>> r300_is_*_supported() end up indirectly calling
>> r300_unbyteswap_array_format(), so it looks like nothing specific is
>> needed for advertisement?
>>
>> > Did you confirm that there are no
>> > piglit gpu profile regressions with this patch?
>>
>> I don't have the hardware and can't test, I just have confirmation
>> from a user that the regression gets fixed.
>>
>> Gražvydas
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/mesa-dev/attachments/20170214/5231d1e3/attachment.html>