[Mesa-dev] [PATCH] r300g: set endian controls on big endian

[Marek Olšák]

On Sun, May 1, 2016 at 2:43 PM, Michel Dänzer <michel at daenzer.net> wrote:
> On 24.04.2016 20:27, Marek Olšák wrote:
>> From: Marek Olšák <marek.olsak at amd.com>
>>
>> ---
>>  src/gallium/drivers/r300/r300_reg.h     | 20 +++++++----------
>>  src/gallium/drivers/r300/r300_texture.c | 38 ++++++++++++++++++++++++++++++---
>>  2 files changed, 43 insertions(+), 15 deletions(-)
>>
>> diff --git a/src/gallium/drivers/r300/r300_reg.h b/src/gallium/drivers/r300/r300_reg.h
>> index 9c373c5..9c93b84 100644
>> --- a/src/gallium/drivers/r300/r300_reg.h
>> +++ b/src/gallium/drivers/r300/r300_reg.h
>> @@ -1700,10 +1700,7 @@ USE OR OTHER DEALINGS IN THE SOFTWARE.
>>  #define R300_TX_OFFSET_6                    0x4558
>>  #define R300_TX_OFFSET_7                    0x455C
>>
>> -#       define R300_TXO_ENDIAN_NO_SWAP           (0 << 0)
>> -#       define R300_TXO_ENDIAN_BYTE_SWAP         (1 << 0)
>> -#       define R300_TXO_ENDIAN_WORD_SWAP         (2 << 0)
>> -#       define R300_TXO_ENDIAN_HALFDW_SWAP       (3 << 0)
>> +#       define R300_TXO_ENDIAN(x)                ((x) << 0)
>>  #       define R300_TXO_MACRO_TILE_LINEAR        (0 << 2)
>>  #       define R300_TXO_MACRO_TILE_TILED         (1 << 2)
>>  #       define R300_TXO_MACRO_TILE(x)            ((x) << 2)
>> @@ -2418,10 +2415,7 @@ USE OR OTHER DEALINGS IN THE SOFTWARE.
>>  #       define R300_COLOR_MICROTILE_ENABLE        (1 << 17)
>>  #       define R300_COLOR_MICROTILE_ENABLE_SQUARE (2 << 17) /* Only available in 16-bit */
>>  #       define R300_COLOR_MICROTILE(x)            ((x) << 17)
>> -#       define R300_COLOR_ENDIAN_NO_SWAP          (0 << 19)
>> -#       define R300_COLOR_ENDIAN_WORD_SWAP        (1 << 19)
>> -#       define R300_COLOR_ENDIAN_DWORD_SWAP       (2 << 19)
>> -#       define R300_COLOR_ENDIAN_HALF_DWORD_SWAP  (3 << 19)
>> +#       define R300_COLOR_ENDIAN(x)               ((x) << 19)
>>  #    define R500_COLOR_FORMAT_ARGB10101010     (0 << 21)
>>  #    define R500_COLOR_FORMAT_UV1010           (1 << 21)
>>  #    define R500_COLOR_FORMAT_CI8              (2 << 21) /* 2D only */
>
> Did you or anyone else test this patch? Back when I fixed the classic
> r300 driver to work on big endian hosts, none of these bits seemed to
> have any effect unfortunately. It's possible I did something wrong then
> though.

Yes and the patch doesn't work. (bugzilla contains an updated patch that works)

I think the reason the endian bits didn't work for you is that you set
the swizzle according to u_format.csv and also the endian swap, so the
component order was reversed twice. This is the correct way, compare:

BGRA implementation:
- program everything like BGRA
- set endian swap to 0
- works the same on LE and BE, because it's an array format

ARGB implementation:
- program everything like BGRA (I mean EVERYTHING)
- set endian swap to DWORD swap
- works the same on LE and BE, because it's an array format

And my latest patch does exactly that.

Marek