From 63495f6b4aede26e6f8fe3da69e5cfdd8a4ccc3b Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Thu, 29 Oct 2020 13:25:21 +0100 Subject: [PATCH] drm/vc4: hdmi: Make sure our clock rate is within limits The HDMI controller cannot go above a certain pixel rate limit depending on the generations, but that limit is only enforced in mode_valid at the moment, which means that we won't advertise modes that exceed that limit, but the userspace is still free to try to setup a mode that would. Implement atomic_check to make sure we check it in that scenario too. Signed-off-by: Maxime Ripard Reviewed-by: Dave Stevenson Link: https://patchwork.freedesktop.org/patch/msgid/20201029122522.1917579-1-maxime@cerno.tech --- drivers/gpu/drm/vc4/vc4_hdmi.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c index 95779d5..600dd6d 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -760,6 +760,20 @@ static void vc4_hdmi_encoder_enable(struct drm_encoder *encoder) { } +static int vc4_hdmi_encoder_atomic_check(struct drm_encoder *encoder, + struct drm_crtc_state *crtc_state, + struct drm_connector_state *conn_state) +{ + struct drm_display_mode *mode = &crtc_state->adjusted_mode; + struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder); + unsigned long long pixel_rate = mode->clock * 1000; + + if (pixel_rate > vc4_hdmi->variant->max_pixel_clock) + return -EINVAL; + + return 0; +} + static enum drm_mode_status vc4_hdmi_encoder_mode_valid(struct drm_encoder *encoder, const struct drm_display_mode *mode) @@ -773,6 +787,7 @@ vc4_hdmi_encoder_mode_valid(struct drm_encoder *encoder, } static const struct drm_encoder_helper_funcs vc4_hdmi_encoder_helper_funcs = { + .atomic_check = vc4_hdmi_encoder_atomic_check, .mode_valid = vc4_hdmi_encoder_mode_valid, .disable = vc4_hdmi_encoder_disable, .enable = vc4_hdmi_encoder_enable, -- 2.7.4