openwrt/target/linux/bcm27xx/patches-6.6/950-1225-drm-vc4-Add-a-delay-after-disabling-hdmi-phy-output.patch
Álvaro Fernández Rojas 538a1d740c bcm27xx: update to latest RPi patches
The patches were generated from the RPi repo with the following command:
git format-patch v6.6.58..rpi-6.6.y

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
2024-10-31 13:44:23 +01:00

35 lines
1.1 KiB
Diff

From d984fd8907736d37656c558e213cfe087e43a7ce Mon Sep 17 00:00:00 2001
From: Dom Cobley <popcornmix@gmail.com>
Date: Mon, 12 Aug 2024 13:31:58 +0100
Subject: [PATCH 1225/1350] drm/vc4: Add a delay after disabling hdmi phy
output
There appears to be a requirement for some devices
(I'm testing with a 8K VRROOM 40Gbps HDMI switch)
for a measable delay between removing the hdmi phy output from
the old mode, to enabling the hdmi phy output for the new mode.
Without the delay, a mode switch has a small change of getting a permanent
'no signal', which requires a subsequent mode switch or a unplug/replug
to redetect.
Switching between 4kp24/25/30 modes fails about 5% of time in my testing.
Add a delay to make it impossible to switch faster than this.
Signed-off-by: Dom Cobley <popcornmix@gmail.com>
---
drivers/gpu/drm/vc4/vc4_crtc.c | 1 +
1 file changed, 1 insertion(+)
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -668,6 +668,7 @@ static void vc4_crtc_atomic_disable(stru
* someone was waiting it.
*/
vc4_crtc_send_vblank(crtc);
+ msleep(20);
}
static void vc4_crtc_atomic_enable(struct drm_crtc *crtc,