[PATCH 8/9] drm/vc4: hdmi: Introduce an output_enabled flag

From: Maxime Ripard <maxime@cerno.tech>
To: Daniel Vetter <daniel.vetter@intel.com>,
	David Airlie <airlied@linux.ie>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Thomas Zimmermann <tzimmermann@suse.de>,
	Maxime Ripard <maxime@cerno.tech>
Cc: Dave Stevenson <dave.stevenson@raspberrypi.com>,
	Phil Elwell <phil@raspberrypi.com>,
	Tim Gover <tim.gover@raspberrypi.com>,
	Dom Cobley <dom@raspberrypi.com>,
	dri-devel@lists.freedesktop.org,
	Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Subject: [PATCH 8/9] drm/vc4: hdmi: Introduce an output_enabled flag
Date: Mon, 25 Oct 2021 16:11:12 +0200	[thread overview]
Message-ID: <20211025141113.702757-9-maxime@cerno.tech> (raw)
In-Reply-To: <20211025141113.702757-1-maxime@cerno.tech>

We currently poke at encoder->crtc in the ALSA code path to determine
whether the HDMI output is enabled or not, and thus whether we should
allow the audio output.

However, that pointer is deprecated and shouldn't really be used by
atomic drivers anymore. Since we have the infrastructure in place now,
let's just create a flag that we toggle to report whether the controller
is currently enabled and use that instead of encoder->crtc in ALSA.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 16 ++++++++++++----
 drivers/gpu/drm/vc4/vc4_hdmi.h |  6 ++++++
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 291fad018be3..8fb8e7e57f9c 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -724,6 +724,11 @@ static void vc4_hdmi_encoder_post_crtc_powerdown(struct drm_encoder *encoder,
 
 static void vc4_hdmi_encoder_disable(struct drm_encoder *encoder)
 {
+	struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
+
+	mutex_lock(&vc4_hdmi->mutex);
+	vc4_hdmi->output_enabled = false;
+	mutex_unlock(&vc4_hdmi->mutex);
 }
 
 static void vc4_hdmi_csc_setup(struct vc4_hdmi *vc4_hdmi, bool enable)
@@ -1217,6 +1222,11 @@ static void vc4_hdmi_encoder_post_crtc_enable(struct drm_encoder *encoder,
 
 static void vc4_hdmi_encoder_enable(struct drm_encoder *encoder)
 {
+	struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
+
+	mutex_lock(&vc4_hdmi->mutex);
+	vc4_hdmi->output_enabled = true;
+	mutex_unlock(&vc4_hdmi->mutex);
 }
 
 static void vc4_hdmi_encoder_atomic_mode_set(struct drm_encoder *encoder,
@@ -1396,14 +1406,12 @@ static inline struct vc4_hdmi *dai_to_hdmi(struct snd_soc_dai *dai)
 
 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 the controller is disabled, prevent any ALSA output.
 	 */
-	if (!encoder->crtc)
+	if (!vc4_hdmi->output_enabled)
 		return false;
 
 	/*
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.h b/drivers/gpu/drm/vc4/vc4_hdmi.h
index a43cc5614d19..5d3e97703e8d 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.h
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.h
@@ -203,6 +203,12 @@ struct vc4_hdmi {
 	 * for use by ALSA hooks and interrupt handlers. Protected by @mutex.
 	 */
 	struct drm_display_mode saved_adjusted_mode;
+
+	/**
+	 * @output_enabled: Is the HDMI controller currently active?
+	 * Protected by @mutex.
+	 */
+	bool output_enabled;
 };
 
 static inline struct vc4_hdmi *
-- 
2.31.1

