bcm27xx: add support for linux v5.15

Build system: x86_64
Build-tested: bcm2708, bcm2709, bcm2710, bcm2711
Run-tested: bcm2708/RPiB+, bcm2709/RPi3B, bcm2710/RPi3B, bcm2711/RPi4B

Signed-off-by: Marty Jones <mj8263788@gmail.com>
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

1 files changed, 57 insertions, 0 deletions

diff --git a/target/linux/bcm27xx/patches-5.15/950-0441-drm-vc4-Increase-the-core-clock-based-on-HVS-load.patch b/target/linux/bcm27xx/patches-5.15/950-0441-drm-vc4-Increase-the-core-clock-based-on-HVS-load.patch
new file mode 100644
index 0000000000..b184172f8d
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.15/950-0441-drm-vc4-Increase-the-core-clock-based-on-HVS-load.patch
@@ -0,0 +1,57 @@
+From 7971426f2462b02ea1bf12d902ca066e07eeb64b Mon Sep 17 00:00:00 2001
+From: Maxime Ripard <maxime@cerno.tech>
+Date: Wed, 26 May 2021 16:13:02 +0200
+Subject: [PATCH] drm/vc4: Increase the core clock based on HVS load
+
+Depending on a given HVS output (HVS to PixelValves) and input (planes
+attached to a channel) load, the HVS needs for the core clock to be
+raised above its boot time default.
+
+Failing to do so will result in a vblank timeout and a stalled display
+pipeline.
+
+Signed-off-by: Maxime Ripard <maxime@cerno.tech>
+---
+ drivers/gpu/drm/vc4/vc4_drv.h |  1 +
+ drivers/gpu/drm/vc4/vc4_kms.c | 13 +++++++++++++
+ 2 files changed, 14 insertions(+)
+
+--- a/drivers/gpu/drm/vc4/vc4_drv.h
++++ b/drivers/gpu/drm/vc4/vc4_drv.h
+@@ -321,6 +321,7 @@ struct vc4_hvs {
+ 	u32 __iomem *dlist;
+ 
+ 	struct clk *core_clk;
++	struct clk_request *core_req;
+ 
+ 	/* Memory manager for CRTCs to allocate space in the display
+ 	 * list.  Units are dwords.
+--- a/drivers/gpu/drm/vc4/vc4_kms.c
++++ b/drivers/gpu/drm/vc4/vc4_kms.c
+@@ -391,6 +391,11 @@ static void vc4_atomic_commit_tail(struc
+ 						new_hvs_state->core_clock_rate);
+ 
+ 		core_req = clk_request_start(hvs->core_clk, core_rate);
++		/*
++		 * And remove the previous one based on the HVS
++		 * requirements if any.
++		 */
++               clk_request_done(hvs->core_req);
+ 	}
+ 
+ 	drm_atomic_helper_commit_modeset_disables(dev, state);
+@@ -418,6 +423,14 @@ static void vc4_atomic_commit_tail(struc
+ 		drm_dbg(dev, "Running the core clock at %lu Hz\n",
+ 			new_hvs_state->core_clock_rate);
+ 
++		/*
++		 * Request a clock rate based on the current HVS
++		 * requirements.
++		 */
++		hvs->core_req = clk_request_start(hvs->core_clk,
++						  new_hvs_state->core_clock_rate);
++
++		/* And drop the temporary request */
+ 		clk_request_done(core_req);
+ 	}
+ }