openwrtv4/target/linux/brcm2708/patches-4.4/0519-drm-vc4-Enable-Disable-vblanks-properly-in-crtc-en-d.patch

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From c4bd9665b145cacfdf9cbd5f3d83ed0961080236 Mon Sep 17 00:00:00 2001
From: Mario Kleiner <mario.kleiner.de@gmail.com>
Date: Tue, 19 Jul 2016 20:59:01 +0200
Subject: [PATCH] drm/vc4: Enable/Disable vblanks properly in crtc en/disable.
Add missing drm_crtc_vblank_on/off() calls so vblank irq
handling/updating/timestamping never runs with a crtc shut down
or during its shutdown/startup, as that causes large jumps in
vblank count and trouble for compositors.
Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
---
drivers/gpu/drm/vc4/vc4_crtc.c | 6 ++++++
1 file changed, 6 insertions(+)
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -468,6 +468,9 @@ static void vc4_crtc_disable(struct drm_
int ret;
require_hvs_enabled(dev);
+ /* Disable vblank irq handling before crtc is disabled. */
+ drm_crtc_vblank_off(crtc);
+
if (VC4_DSI_USE_FIRMWARE_SETUP &&
(CRTC_READ(PV_V_CONTROL) & PV_VCONTROL_DSI)) {
/* Skip disabling the PV/HVS for the channel if it was
@@ -531,6 +534,9 @@ static void vc4_crtc_enable(struct drm_c
/* Turn on the pixel valve, which will emit the vstart signal. */
CRTC_WRITE(PV_V_CONTROL,
CRTC_READ(PV_V_CONTROL) | PV_VCONTROL_VIDEN);
+
+ /* Enable vblank irq handling after crtc is started. */
+ drm_crtc_vblank_on(crtc);
}
static bool vc4_crtc_mode_fixup(struct drm_crtc *crtc,