[PATCH 0/2] Fix AST2500 graphics on ppc64 systems in big-endian mode

[Thomas Zimmermann]

Hi,

please take a look at the patch at [1]. Testing is welcome, if you can.

Best regards
Thomas

[1] 
https://lore.kernel.org/dri-devel/20251202.170626.2134482663677806825.rene@exactco.de/

Am 17.10.25 um 20:17 schrieb Timothy Pearson:
> On ppc64 systems that use the AST2500 graphics device, such as the Blackbird
> POWER9 system, the red and blue channels are inverted when the host is running
> in big endian mode.  This is due to a ppc64 hardware quirk, which when combined
> with a hardware design fault in the AST2500 VGA controller results in a need
> to use software-based red-blue channel swapping.
>
> Tested to fix color graphics on Debian sid/ppc64 on a Blackbird system.
>
> Timothy Pearson (2):
>    PCI: Add CONFIG_PCI_ARCH_ENDIAN_AUTOSWAP
>    drm/ast: Fix framebuffer color swapping on ppc64 systems
>
>   arch/powerpc/Kconfig           |  1 +
>   drivers/gpu/drm/ast/ast_mode.c | 33 +++++++++++++++++++++++++++++++--
>   drivers/pci/Kconfig            |  4 ++++
>   3 files changed, 36 insertions(+), 2 deletions(-)
>

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)