From: Maxime Ripard <maxime@cerno.tech>
Date: Thu, 29 Oct 2020 13:25:21 +0100
Subject: drm/vc4: hdmi: Make sure our clock rate is within limits
Git-commit: 63495f6b4aede26e6f8fe3da69e5cfdd8a4ccc3b
Patch-mainline: v5.10-rc6
References: jsc#SLE-15318
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 <maxime@cerno.tech>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201029122522.1917579-1-maxime@cerno.tech
Acked-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---
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 95779d50cca0..600dd6d40309 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,