openwrt/target/linux/bcm27xx/patches-5.15/950-0621-drm-vc4-hvs-Ignore-atomic_flush-if-we-re-disabled.patch

From ba067c30a6456a28c42f74d2134ce9a54a10337f Mon Sep 17 00:00:00 2001
From: Maxime Ripard <maxime@cerno.tech>
Date: Mon, 6 Dec 2021 16:32:10 +0100
Subject: [PATCH] drm/vc4: hvs: Ignore atomic_flush if we're disabled

atomic_flush will be called for each CRTC even if they aren't enabled.

The whole code we have there will thus run without a properly affected
channel, which can then result in all sorts of weird behaviour.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 drivers/gpu/drm/vc4/vc4_hvs.c | 3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/gpu/drm/vc4/vc4_hvs.c
+++ b/drivers/gpu/drm/vc4/vc4_hvs.c
@@ -709,6 +709,9 @@ void vc4_hvs_atomic_flush(struct drm_crt
 	u32 __iomem *dlist_start = vc4->hvs->dlist + vc4_state->mm.start;
 	u32 __iomem *dlist_next = dlist_start;
 
+	if (vc4_state->assigned_channel == VC4_HVS_CHANNEL_DISABLED)
+		return;
+
 	if (debug_dump_regs) {
 		DRM_INFO("CRTC %d HVS before:\n", drm_crtc_index(crtc));
 		vc4_hvs_dump_state(dev);