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[7/9] drm/vc4: hdmi: Check the device state in prepare()

Message ID 20211025141113.702757-8-maxime@cerno.tech (mailing list archive)
State New, archived
Headers show
Series drm/vc4: Introduce locking and remove !KMS state access | expand

Commit Message

Maxime Ripard Oct. 25, 2021, 2:11 p.m. UTC
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(-)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index cb444571a3f7..291fad018be3 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -1394,20 +1394,36 @@  static inline struct vc4_hdmi *dai_to_hdmi(struct snd_soc_dai *dai)
 	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;
 	}
@@ -1537,6 +1553,11 @@  static int vc4_hdmi_audio_prepare(struct device *dev, void *data,
 
 	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);