drm/amdgpu: Fix overflow of watermark calcs at > 4k resolutions.

commit bea1041393 upstream.

Commit d63c277dc6
("drm/amdgpu: Make display watermark calculations more accurate")
made watermark calculations more accurate, but not for > 4k
resolutions on 32-Bit architectures, as it introduced an integer
overflow for those setups and resolutions.

Fix this by proper u64 casting and division.

Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Fixes: d63c277dc6 ("drm/amdgpu: Make display watermark calculations more accurate")
Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mario Kleiner 2017-06-13 07:17:10 +02:00 • committed by Greg Kroah-Hartman
commit 7f7bb1173d
4 changed files with 20 additions and 8 deletions