Consider upgrading Mesa

[linkmauve]

The current version is 2:24.1.7-2, which is almost two years old.

I don’t know if support for my ATI Mobility Radeon 9550 improved since then, but it is currently completely broken, with both ARGB<->BGRA inversion, and tiling gone wrong:

[kth5]

Anything after 24.x will not function well or at all on big-endian with r300 and prior chipsets which are very dominent on most of ArchPOWER's users' systems. There is ongoing work you may follow along on Discord.

Above is an iBook, so probably sports a Radeon 9200 derivate in the 9550 you mention. In effect here, try to force using DRI2 and EXA at this time.

And just in case, do not use the modesetting driver but instead ensure xf86-video-ati's radeon is in use.