[PATCH v7 3/9] drm/vc4: hdmi: Take into account the clock doubling flag in atomic_check

Maxime Ripard maxime at cerno.tech
Tue Dec 15 15:42:37 UTC 2020


Commit 63495f6b4aed ("drm/vc4: hdmi: Make sure our clock rate is within
limits") was intended to compute the pixel rate to make sure we remain
within the boundaries of what the hardware can provide.

However, unlike what mode_valid was checking for, we forgot to take
into account the clock doubling flag that can be set for modes. Let's
honor that flag if it's there.

Acked-by: Thomas Zimmermann <tzimmermann at suse.de>
Reported-by: Thomas Zimmermann <tzimmermann at suse.de>
Reviewed-by: Dave Stevenson <dave.stevenson at raspberrypi.com>
Fixes: 63495f6b4aed ("drm/vc4: hdmi: Make sure our clock rate is within limits")
Signed-off-by: Maxime Ripard <maxime at cerno.tech>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 8ce5dd65f6e4..3dac839b0fa5 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -799,6 +799,9 @@ static int vc4_hdmi_encoder_atomic_check(struct drm_encoder *encoder,
 		pixel_rate = mode->clock * 1000;
 	}
 
+	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
+		pixel_rate = pixel_rate * 2;
+
 	if (pixel_rate > vc4_hdmi->variant->max_pixel_clock)
 		return -EINVAL;
 
-- 
2.29.2



More information about the dri-devel mailing list