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, 96 insertions, 0 deletions

diff --git a/target/linux/bcm27xx/patches-5.15/950-0015-drm-vc4-crtc-Rework-the-encoder-retrieval-code-again.patch b/target/linux/bcm27xx/patches-5.15/950-0015-drm-vc4-crtc-Rework-the-encoder-retrieval-code-again.patch
new file mode 100644
index 0000000000..d247ec2e4f
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.15/950-0015-drm-vc4-crtc-Rework-the-encoder-retrieval-code-again.patch
@@ -0,0 +1,96 @@
+From 0496e855a6e1acd60d4ae2e52ee906a4cffae014 Mon Sep 17 00:00:00 2001
+From: Maxime Ripard <maxime@cerno.tech>
+Date: Mon, 21 Jun 2021 16:07:22 +0200
+Subject: [PATCH] drm/vc4: crtc: Rework the encoder retrieval code
+ (again)
+
+It turns out the encoder retrieval code, in addition to being
+unnecessarily complicated, has a bug when only the planes and crtcs are
+affected by a given atomic commit.
+
+Indeed, in such a case, either drm_atomic_get_old_connector_state or
+drm_atomic_get_new_connector_state will return NULL and thus our encoder
+retrieval code will not match on anything.
+
+We can however simplify the code by using drm_for_each_encoder_mask, the
+drm_crtc_state storing the encoders a given CRTC is connected to
+directly and without relying on any other state.
+
+Signed-off-by: Maxime Ripard <maxime@cerno.tech>
+---
+ drivers/gpu/drm/vc4/vc4_crtc.c | 30 +++++++++---------------------
+ drivers/gpu/drm/vc4/vc4_drv.h  |  4 +---
+ 2 files changed, 10 insertions(+), 24 deletions(-)
+
+--- a/drivers/gpu/drm/vc4/vc4_crtc.c
++++ b/drivers/gpu/drm/vc4/vc4_crtc.c
+@@ -282,26 +282,14 @@ static u32 vc4_crtc_get_fifo_full_level_
+  * same CRTC.
+  */
+ struct drm_encoder *vc4_get_crtc_encoder(struct drm_crtc *crtc,
+-					 struct drm_atomic_state *state,
+-					 struct drm_connector_state *(*get_state)(struct drm_atomic_state *state,
+-										  struct drm_connector *connector))
++					 struct drm_crtc_state *state)
+ {
+-	struct drm_connector *connector;
+-	struct drm_connector_list_iter conn_iter;
++	struct drm_encoder *encoder;
+ 
+-	drm_connector_list_iter_begin(crtc->dev, &conn_iter);
+-	drm_for_each_connector_iter(connector, &conn_iter) {
+-		struct drm_connector_state *conn_state = get_state(state, connector);
+-
+-		if (!conn_state)
+-			continue;
+-
+-		if (conn_state->crtc == crtc) {
+-			drm_connector_list_iter_end(&conn_iter);
+-			return connector->encoder;
+-		}
+-	}
+-	drm_connector_list_iter_end(&conn_iter);
++	WARN_ON(hweight32(state->encoder_mask) > 1);
++
++	drm_for_each_encoder_mask(encoder, crtc->dev, state->encoder_mask)
++		return encoder;
+ 
+ 	return NULL;
+ }
+@@ -552,8 +540,7 @@ static void vc4_crtc_atomic_disable(stru
+ 	struct drm_crtc_state *old_state = drm_atomic_get_old_crtc_state(state,
+ 									 crtc);
+ 	struct vc4_crtc_state *old_vc4_state = to_vc4_crtc_state(old_state);
+-	struct drm_encoder *encoder = vc4_get_crtc_encoder(crtc, state,
+-							   drm_atomic_get_old_connector_state);
++	struct drm_encoder *encoder = vc4_get_crtc_encoder(crtc, old_state);
+ 	struct drm_device *dev = crtc->dev;
+ 
+ 	require_hvs_enabled(dev);
+@@ -580,10 +567,11 @@ static void vc4_crtc_atomic_disable(stru
+ static void vc4_crtc_atomic_enable(struct drm_crtc *crtc,
+ 				   struct drm_atomic_state *state)
+ {
++	struct drm_crtc_state *new_state = drm_atomic_get_new_crtc_state(state,
++									 crtc);
+ 	struct drm_device *dev = crtc->dev;
+ 	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
+-	struct drm_encoder *encoder = vc4_get_crtc_encoder(crtc, state,
+-							   drm_atomic_get_new_connector_state);
++	struct drm_encoder *encoder = vc4_get_crtc_encoder(crtc, new_state);
+ 	struct vc4_encoder *vc4_encoder = to_vc4_encoder(encoder);
+ 
+ 	require_hvs_enabled(dev);
+--- a/drivers/gpu/drm/vc4/vc4_drv.h
++++ b/drivers/gpu/drm/vc4/vc4_drv.h
+@@ -545,9 +545,7 @@ vc4_crtc_to_vc4_pv_data(const struct vc4
+ }
+ 
+ struct drm_encoder *vc4_get_crtc_encoder(struct drm_crtc *crtc,
+-					 struct drm_atomic_state *state,
+-					 struct drm_connector_state *(*get_state)(struct drm_atomic_state *state,
+-										  struct drm_connector *connector));
++					 struct drm_crtc_state *state);
+ 
+ struct vc4_crtc_state {
+ 	struct drm_crtc_state base;