openwrt/target/linux/bcm27xx/patches-5.15/950-0617-drm-vc4-kms-Take-old-state-core-clock-rate-into-acco.patch

From ae03b35cf2792e7c4cf55c44dc37322487b72d1d Mon Sep 17 00:00:00 2001
From: Maxime Ripard <maxime@cerno.tech>
Date: Thu, 18 Nov 2021 14:04:00 +0100
Subject: [PATCH] drm/vc4: kms: Take old state core clock rate into
 account

During a commit, the core clock, which feeds the HVS, needs to run at
a minimum of 500MHz.

While doing that commit, we can also change the mode to one that
requires a higher core clock, so we take the core clock rate associated
to that new state into account for that boost.

However, the old state also needs to be taken into account if it
requires a core clock higher that the new one and our 500MHz limit,
since it's still live in hardware at the beginning of our commit.

Fixes: 16e101051f32 ("drm/vc4: Increase the core clock based on HVS load")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 drivers/gpu/drm/vc4/vc4_kms.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/vc4/vc4_kms.c
+++ b/drivers/gpu/drm/vc4/vc4_kms.c
@@ -390,9 +390,10 @@ static void vc4_atomic_commit_tail(struc
 	}
 
 	if (vc4->hvs && vc4->hvs->hvs5) {
+		unsigned long state_rate = max(old_hvs_state->core_clock_rate,
+					       new_hvs_state->core_clock_rate);
 		unsigned long core_rate = max_t(unsigned long,
-						500000000,
-						new_hvs_state->core_clock_rate);
+						500000000, state_rate);
 
 		core_req = clk_request_start(hvs->core_clk, core_rate);
 		/*