When using the modes that need the highest pixel rate we support (such as 4k at 60Hz), using a 10 or 12 bpc output will put us over the limit of what we can achieve.
In such a case, let's force our output to be YUV422 so that we can go back down under the required clock rate.
Signed-off-by: Maxime Ripard maxime@cerno.tech --- drivers/gpu/drm/vc4/vc4_hdmi.c | 37 +++++++++++++++++++++++++++++++++- 1 file changed, 36 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c index c4f91d39d91c..12eda1e76338 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -1029,6 +1029,41 @@ static unsigned long vc4_hdmi_calc_pixel_rate(struct drm_bridge *bridge, return pixel_rate; }
+static u32 *vc4_hdmi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge, + struct drm_bridge_state *bridge_state, + struct drm_crtc_state *crtc_state, + struct drm_connector_state *conn_state, + unsigned int *num_output_fmts) +{ + struct vc4_hdmi *vc4_hdmi = bridge_to_vc4_hdmi(bridge); + unsigned long long pixel_rate = vc4_hdmi_calc_pixel_rate(bridge, + bridge_state, + crtc_state, + conn_state); + + /* + * If our pixel rate is too fast, force YUV422 and hope it works + */ + if (pixel_rate > vc4_hdmi->variant->max_pixel_clock) { + u32 *output_fmts; + + output_fmts = kzalloc(sizeof(*output_fmts), GFP_KERNEL); + if (!output_fmts) + return NULL; + + *output_fmts = MEDIA_BUS_FMT_UYVY8_1X16; + *num_output_fmts = 1; + + return output_fmts; + } + + return drm_atomic_helper_bridge_hdmi_get_output_bus_fmts(bridge, + bridge_state, + crtc_state, + conn_state, + num_output_fmts); +} + static int vc4_hdmi_bridge_atomic_check(struct drm_bridge *bridge, struct drm_bridge_state *bridge_state, struct drm_crtc_state *crtc_state, @@ -1088,7 +1123,7 @@ static const struct drm_bridge_funcs vc4_hdmi_bridge_funcs = { .atomic_check = vc4_hdmi_bridge_atomic_check, .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state, .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state, - .atomic_get_output_bus_fmts = drm_atomic_helper_bridge_hdmi_get_output_bus_fmts, + .atomic_get_output_bus_fmts = vc4_hdmi_bridge_atomic_get_output_bus_fmts, .atomic_reset = drm_atomic_helper_bridge_reset, .mode_valid = vc4_hdmi_bridge_mode_valid, };