On 2022-07-12 11:03, Gerd Hoffmann wrote:
As described above DRM_FORMAT_HOST_RGB565 means bigendian on bigendian
hosts and little endian on little endian hosts. Which is not correct
when your hardware does big endian no matter what.
But (a) drm_driver_legacy_fb_format() uses DRM_FORMAT_HOST_RGB565
if quirk_addfb_prefer_host_byte_order is set,
Ah, right. Missed that in 'git grep' output. Given that traditional
fbdev behavior is to expect native byte order using
DRM_FORMAT_HOST_RGB565 there makes sense indeed.
Scratch my comment about it being unused then ;)
DRM_FORMAT_RGB565 | DRM_FORMAT_BIG_ENDIAN is still what the driver should use conceptually, and should match DRM_FORMAT_HOST_RGB565 in drm_driver_legacy_fb_format on a big endian host (which is presumably always the case for the atari driver).
--
Earthling Michel Dänzer | https://redhat.com
Libre software enthusiast | Mesa and Xwayland developer
