[PATCH] drm/rockchip: dw_hdmi: Fix error handling for drm_atomic_get_bridge_state()

[Chen Ni]

The drm_atomic_get_bridge_state() function returns an error pointer on
failure, not NULL. Fix the check to use IS_ERR() to correctly handle
allocation failures.

Fixes: dc70272cc184 ("drm/rockchip: dw_hdmi: Propagate bus format to display 
driver")
Signed-off-by: Chen Ni <nic...@iscas.ac.cn>
---
 drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c 
b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
index cffc0af5190f..766cf21a4be7 100644
--- a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
@@ -287,7 +287,7 @@ static u32 dw_hdmi_rockchip_get_bus_format(struct 
drm_encoder *encoder,
                return 0;
 
        bridge_state = drm_atomic_get_bridge_state(conn_state->state, bridge);
-       if (!bridge_state)
+       if (IS_ERR(bridge_state))
                return 0;
 
        if (bridge_state->input_bus_cfg.format != MEDIA_BUS_FMT_FIXED)
-- 
2.25.1