From: Maxime Ripard <maxime@cerno.tech>
Date: Tue, 15 Dec 2020 16:42:37 +0100
Subject: drm/vc4: hdmi: Take into account the clock doubling flag in
 atomic_check
Git-commit: 320e84dc6111ecc1c957e2b186d4d2bafee6bde2
Patch-mainline: v5.11 or v5.11-rc8 (next release)
References: git-fixes

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@suse.de>
Reported-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Fixes: 63495f6b4aed ("drm/vc4: hdmi: Make sure our clock rate is within limits")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20201215154243.540115-4-maxime@cerno.tech

Acked-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---
 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;