[PATCH 04/24] drm/amd/display: Check null pointers before using dc->clk_mgr

[Tom Chung]

From: Alex Hung <alex.hung at amd.com>

[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 at amd.com>
Signed-off-by: Alex Hung <alex.hung at amd.com>
Signed-off-by: Tom Chung <chiahsuan.chung at amd.com>
---
 drivers/gpu/drm/amd/display/dc/core/dc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
index b1253e4c81a8..3ba2acfdae2a 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
@@ -5425,7 +5425,8 @@ 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;
 }
 
-- 
2.34.1