[PATCH AUTOSEL 6.12 07/31] drm/tests: hdmi: handle empty modes in find_preferred_mode()

[Sasha Levin <sashal@kernel.org>]

From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

[ Upstream commit d3314efd6ebf335a3682b1d6b1b81cdab3d8254a ]

If the connector->modes list is empty, then list_first_entry() returns a
bogus entry. Change that to use list_first_entry_or_null().

Reviewed-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20241130-hdmi-mode-valid-v5-1-742644ec3b1f@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c b/drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c
index 294773342e710..1e77689af6549 100644
--- a/drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c
+++ b/drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c
@@ -46,7 +46,7 @@ static struct drm_display_mode *find_preferred_mode(struct drm_connector *connec
 	struct drm_display_mode *mode, *preferred;
 
 	mutex_lock(&drm->mode_config.mutex);
-	preferred = list_first_entry(&connector->modes, struct drm_display_mode, head);
+	preferred = list_first_entry_or_null(&connector->modes, struct drm_display_mode, head);
 	list_for_each_entry(mode, &connector->modes, head)
 		if (mode->type & DRM_MODE_TYPE_PREFERRED)
 			preferred = mode;
-- 
2.39.5