drm/radeon: avoid bogus "vram limit (0) must be a power of 2" warning

I was getting the following message on boot on Linux 5.19-rc5:
        radeon 0000:01:05.0: vram limit (0) must be a power of 2
(I didn't use any radeon.vramlimit commandline parameter).

This is caused by
commit 8c2d34eb53b9 ("drm/radeon: use kernel is_power_of_2 rather than local version")
which removed radeon_check_pot_argument() and converted its users to
is_power_of_2(). The two functions differ in its handling of 0, which is
the default value of radeon_vram_limit: radeon_check_pot_argument()
"incorrectly" considered it a power of 2, while is_power_of_2() does not.

An appropriate conditional silences the warning message.

It is not necessary to add a similar test to other callers of
is_power_of_2() in radeon_device.c. The matching commit in amdgpu:
commit 761175078466 ("drm/amdgpu: use kernel is_power_of_2 rather than local version")
is unaffected by this bug.

Tested on Radeon HD 3200.

Not ccing stable, this is not serious enough.

Fixes: 8c2d34eb53b9 ("drm/radeon: use kernel is_power_of_2 rather than local version")
Cc: Alex Deucher <[email protected]>
Cc: Christian König <[email protected]>
Cc: "Pan, Xinhui" <[email protected]>
Cc: David Airlie <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: Jonathan Gray <[email protected]>
Signed-off-by: Mateusz Jończyk <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

0 files changed, 0 insertions, 0 deletions