drm/amd/display: Avoid NULL dereference of timing generator

[ Upstream commit b1904ed480 ]

[Why & How]
Check whether assigned timing generator is NULL or not before
accessing its funcs to prevent NULL dereference.

Reviewed-by: Jun Lei <jun.lei@amd.com>
Acked-by: Hersen Wu <hersenxs.wu@amd.com>
Signed-off-by: Wayne Lin <wayne.lin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Wayne Lin 2023-09-08 10:14:49 +08:00 • committed by Greg Kroah-Hartman
commit df8bc953ee