Commit 6d30c0f7 authored Oct 23, 2016 by Russell King

drm/i2c: tda998x: avoid race in tda998x_encoder_mode_set()



As priv->audio_params can now be changed at run time, we need to be more
careful about how we deal with a mode set.  We must take the audio lock
while checking if there's a valid audio configuration.

However, it's slightly worse than that - during mode set, we mute the
audio, and it must not be unmuted until we have finished the mode set.
It is possible that the audio side may start while a mode set is in
progress, so take the audio_mutex lock around the whole mode setting
procedure.

Tested-by: Jon Medhurst <tixy@linaro.org>
Acked-by: Jon Medhurst <tixy@linaro.org>
Tested-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

parent ba300c17

drivers/gpu/drm/i2c/tda998x_drv.c

+3 −4

Original line number	Diff line number	Diff line
		@@ -1074,15 +1074,14 @@ tda998x_encoder_mode_set(struct drm_encoder *encoder,

		tda998x_write_avi(priv, adjusted_mode);

		if (priv->audio_params.format != AFMT_UNUSED) {
		mutex_lock(&priv->audio_mutex);
		if (priv->audio_params.format != AFMT_UNUSED)
		tda998x_configure_audio(priv,
		&priv->audio_params,
		adjusted_mode->clock);
		mutex_unlock(&priv->audio_mutex);
		}
		}
		}

		static enum drm_connector_status
		tda998x_connector_detect(struct drm_connector *connector, bool force)

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