ASoC:soc-pcm:fix a codec fixup issue in TDM case

On HDaudio platforms, if playback is started when capture is working,
there is no audible output.

This can be root-caused to the use of the rx|tx_mask to store an HDaudio
stream tag.

If capture is stared before playback, rx_mask would be non-zero on HDaudio
platform, then the channel number of playback, which is in the same codec
dai with the capture, would be changed by soc_pcm_codec_params_fixup based
on the tx_mask at first, then overwritten by this function based on rx_mask
at last.

According to the author of tx|rx_mask, tx_mask is for playback and rx_mask
is for capture. And stream direction is checked at all other references of
tx|rx_mask in ASoC, so here should be an error. This patch checks stream
direction for tx|rx_mask for fixup function.

This issue would affect not only HDaudio+ASoC, but also I2S codecs if the
channel number based on rx_mask is not equal to the one for tx_mask. It could
be rarely reproduecd because most drivers in kernel set the same channel number
to tx|rx_mask or rx_mask is zero.

Tested on all platforms using stream_tag & HDaudio and intel I2S platforms.

Signed-off-by: Rander Wang <rander.wang@linux.intel.com>
Acked-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c
index a5b40e82dea4ac2bce93fe7dba18f799adc20d04..e70555a4ea069677beb28edf1c280aefb36abe85 100644 (file)
--- a/sound/soc/soc-pcm.c
+++ b/sound/soc/soc-pcm.c
@@ -954,10 +954,13 @@ static int soc_pcm_hw_params(struct snd_pcm_substream *substream,
                codec_params = *params;
 
                /* fixup params based on TDM slot masks */
-               if (codec_dai->tx_mask)
+               if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
+                   codec_dai->tx_mask)
                        soc_pcm_codec_params_fixup(&codec_params,
                                                   codec_dai->tx_mask);
-               if (codec_dai->rx_mask)
+
+               if (substream->stream == SNDRV_PCM_STREAM_CAPTURE &&
+                   codec_dai->rx_mask)
                        soc_pcm_codec_params_fixup(&codec_params,
                                                   codec_dai->rx_mask);