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, 77 insertions, 0 deletions

diff --git a/target/linux/bcm27xx/patches-5.15/950-0010-drm-vc4-hdmi-Check-the-device-state-in-prepare.patch b/target/linux/bcm27xx/patches-5.15/950-0010-drm-vc4-hdmi-Check-the-device-state-in-prepare.patch
new file mode 100644
index 0000000000..dac66f902b
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.15/950-0010-drm-vc4-hdmi-Check-the-device-state-in-prepare.patch
@@ -0,0 +1,77 @@
+From ba0375640d2d82158600a398181bb9f9c3835d0a Mon Sep 17 00:00:00 2001
+From: Maxime Ripard <maxime@cerno.tech>
+Date: Fri, 24 Sep 2021 14:27:38 +0200
+Subject: [PATCH] drm/vc4: hdmi: Check the device state in prepare()
+
+Even though we already check that the encoder->crtc pointer is there
+during in startup(), which is part of the open() path in ASoC, nothing
+guarantees that our encoder state won't change between the time when we
+open the device and the time we prepare it.
+
+Move the sanity checks we do in startup() to a helper and call it from
+prepare().
+
+Fixes: 91e99e113929 ("drm/vc4: hdmi: Register HDMI codec")
+Signed-off-by: Maxime Ripard <maxime@cerno.tech>
+---
+ drivers/gpu/drm/vc4/vc4_hdmi.c | 35 +++++++++++++++++++++++++++-------
+ 1 file changed, 28 insertions(+), 7 deletions(-)
+
+--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
++++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
+@@ -1397,20 +1397,36 @@ static inline struct vc4_hdmi *dai_to_hd
+ 	return snd_soc_card_get_drvdata(card);
+ }
+ 
++static bool vc4_hdmi_audio_can_stream(struct vc4_hdmi *vc4_hdmi)
++{
++	struct drm_encoder *encoder = &vc4_hdmi->encoder.base.base;
++
++	lockdep_assert_held(&vc4_hdmi->mutex);
++
++	/*
++	 * The encoder doesn't have a CRTC until the first modeset.
++	 */
++	if (!encoder->crtc)
++		return false;
++
++	/*
++	 * If the encoder is currently in DVI mode, treat the codec DAI
++	 * as missing.
++	 */
++	if (!(HDMI_READ(HDMI_RAM_PACKET_CONFIG) & VC4_HDMI_RAM_PACKET_ENABLE))
++		return false;
++
++	return true;
++}
++
+ static int vc4_hdmi_audio_startup(struct device *dev, void *data)
+ {
+ 	struct vc4_hdmi *vc4_hdmi = dev_get_drvdata(dev);
+-	struct drm_encoder *encoder = &vc4_hdmi->encoder.base.base;
+ 	unsigned long flags;
+ 
+ 	mutex_lock(&vc4_hdmi->mutex);
+ 
+-	/*
+-	 * If the HDMI encoder hasn't probed, or the encoder is
+-	 * currently in DVI mode, treat the codec dai as missing.
+-	 */
+-	if (!encoder->crtc || !(HDMI_READ(HDMI_RAM_PACKET_CONFIG) &
+-				VC4_HDMI_RAM_PACKET_ENABLE)) {
++	if (!vc4_hdmi_audio_can_stream(vc4_hdmi)) {
+ 		mutex_unlock(&vc4_hdmi->mutex);
+ 		return -ENODEV;
+ 	}
+@@ -1540,6 +1556,11 @@ static int vc4_hdmi_audio_prepare(struct
+ 
+ 	mutex_lock(&vc4_hdmi->mutex);
+ 
++	if (!vc4_hdmi_audio_can_stream(vc4_hdmi)) {
++		mutex_unlock(&vc4_hdmi->mutex);
++		return -EINVAL;
++	}
++
+ 	vc4_hdmi_audio_set_mai_clock(vc4_hdmi, sample_rate);
+ 
+ 	spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);