On a PowerPC machine, when Open Firmware Frame Buffer is used (OFfb), I cannot `modprobe radeonfb` (but I can load `radeon`). It currently fails with: [ 96.551486] radeonfb 0000:00:10.0: enabling device (0006 -> 0007) [ 96.551526] radeonfb 0000:00:10.0: BAR 0: can't reserve [mem 0x98000000-0x9fffffff pref] [ 96.551531] radeonfb (0000:00:10.0): cannot request region 0. [ 96.551545] radeonfb: probe of 0000:00:10.0 failed with error -16 It seems (to me) that it should be possible to add something like this to `radeonfb`: https://github.com/torvalds/linux/blob/master/drivers/gpu/drm/radeon/radeon_drv.c#L353 [...] /* Get rid of things like offb */ ret = radeon_kick_out_firmware_fb(pdev); if (ret) [...]
As additional comment, the naive approach of integrating the code from module radeon into radeonfb module did not work, as mentionned in: https://lists.ozlabs.org/pipermail/linuxppc-dev/2016-October/149375.html