From: Yakir Yang ykk@rock-chips.com
Commit 3424e3a4f844 ("drm: bridge: analogix/dp: split exynos dp driver to bridge directory") split the Exynos DP core driver into a core driver and a bridge driver for the Analogix chip since that is also used by Rockchip.
But the change introduced a regression causing a NULL pointer dereference when trying to access an uninitialized connector in the driver .get_modes:
Fix this by instead of having a connector struct for both the Exynos and Analogix drivers, just use the connector initialized in the bridge driver.
Fixes: 3424e3a4f844 ("drm: bridge: analogix/dp: split exynos dp driver to bridge directory") Reported-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Yakir Yang ykk@rock-chips.com [javier: wrote commit message] Signed-off-by: Javier Martinez Canillas javier@osg.samsung.com Tested-by: Marc Zyngier marc.zyngier@arm.com
--- Hello Inki,
This is a regression introduced in v4.7-rc1, so $SUBJECT is -rc material.
Best regards, Javier
drivers/gpu/drm/exynos/exynos_dp.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/exynos/exynos_dp.c b/drivers/gpu/drm/exynos/exynos_dp.c index 468498e3fec1..4c1fb3f8b5a6 100644 --- a/drivers/gpu/drm/exynos/exynos_dp.c +++ b/drivers/gpu/drm/exynos/exynos_dp.c @@ -34,7 +34,7 @@
struct exynos_dp_device { struct drm_encoder encoder; - struct drm_connector connector; + struct drm_connector *connector; struct drm_bridge *ptn_bridge; struct drm_device *drm_dev; struct device *dev; @@ -70,7 +70,7 @@ static int exynos_dp_poweroff(struct analogix_dp_plat_data *plat_data) static int exynos_dp_get_modes(struct analogix_dp_plat_data *plat_data) { struct exynos_dp_device *dp = to_dp(plat_data); - struct drm_connector *connector = &dp->connector; + struct drm_connector *connector = dp->connector; struct drm_display_mode *mode; int num_modes = 0;
@@ -103,6 +103,7 @@ static int exynos_dp_bridge_attach(struct analogix_dp_plat_data *plat_data, int ret;
drm_connector_register(connector); + dp->connector = connector;
/* Pre-empt DP connector creation if there's a bridge */ if (dp->ptn_bridge) {