[PATCH 5.10 143/663] drm/vc4: hdmi: Take into account the clock doubling flag in atomic_check

From: Greg Kroah-Hartman
Date: Mon Mar 01 2021 - 22:43:28 EST


From: Maxime Ripard <maxime@xxxxxxxxxx>

[ Upstream commit 320e84dc6111ecc1c957e2b186d4d2bafee6bde2 ]

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@xxxxxxx>
Reported-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
Reviewed-by: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx>
Fixes: 63495f6b4aed ("drm/vc4: hdmi: Make sure our clock rate is within limits")
Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20201215154243.540115-4-maxime@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 eaba98e15de46..db06f52de9d91 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -791,6 +791,9 @@ 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;

--
2.27.0