drm/amd/display: Check null pointers before using dc->clk_mgr

[ Upstream commit 95d9e0803e51d5a24276b7643b244c7477daf463 ]

[WHY & HOW]
dc->clk_mgr is null checked previously in the same function, indicating
it might be null.

Passing "dc" to "dc->hwss.apply_idle_power_optimizations", which
dereferences null "dc->clk_mgr". (The function pointer resolves to
"dcn35_apply_idle_power_optimizations".)

This fixes 1 FORWARD_NULL issue reported by Coverity.

Reviewed-by: Rodrigo Siqueira <rodrigo.siqueira@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Tom Chung <chiahsuan.chung@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>

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
index 3bd18e862945f4c8cdc01749d94ca6e1e1f52946..daeb80abf435f2483659e63a0c3d166769504e0a 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/core/dc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
@@ -5211,7 +5211,8 @@ void dc_allow_idle_optimizations_internal(struct dc *dc, bool allow, char const
        if (allow == dc->idle_optimizations_allowed)
                return;
 
-       if (dc->hwss.apply_idle_power_optimizations && dc->hwss.apply_idle_power_optimizations(dc, allow))
+       if (dc->hwss.apply_idle_power_optimizations && dc->clk_mgr != NULL &&
+           dc->hwss.apply_idle_power_optimizations(dc, allow))
                dc->idle_optimizations_allowed = allow;
 }