From b6095716b9e7d3d84c76bfb5008ea291847ebd0a Mon Sep 17 00:00:00 2001 From: Andy Green Date: Wed, 19 Nov 2008 17:09:51 +0000 Subject: workaround-s3c24xx-i2s-stop-live-stream-stall-on-resume.patch Reported-by: Graeme Gregory Basically-solved-by: Graeme Gregory Graeme found a while back that on resume, IISCON register in s3c2442 does not show LRCK toggling in LRINDEX bit any more, causing s3c24xx_snd_lrsync() to timeout and return an error, aborting restart of any live stream that was playing at suspend. I confirmed it was true, meddled around for a bit looking for some magic to restart LRCK or at least the reporting of it, and in the end worked around it using the method noted by Graeme: just ignore LRCK sync if it timed out. The worst that could happen would be L and R swap for the duration of stream that was suspended into but probably not even that. Signed-off-by: Andy Green --- sound/soc/s3c24xx/s3c24xx-i2s.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/sound/soc/s3c24xx/s3c24xx-i2s.c b/sound/soc/s3c24xx/s3c24xx-i2s.c index ba4476b55fb..49f1dd18ce3 100644 --- a/sound/soc/s3c24xx/s3c24xx-i2s.c +++ b/sound/soc/s3c24xx/s3c24xx-i2s.c @@ -175,7 +175,7 @@ static void s3c24xx_snd_rxctrl(int on) static int s3c24xx_snd_lrsync(void) { u32 iiscon; - int timeout = 50; /* 5ms */ + int timeout = 5; /* 500us, 125 should be enough at 8kHz */ DBG("Entered %s\n", __func__); @@ -282,11 +282,14 @@ static int s3c24xx_i2s_trigger(struct snd_pcm_substream *substream, int cmd) case SNDRV_PCM_TRIGGER_START: case SNDRV_PCM_TRIGGER_RESUME: case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: - if (!s3c24xx_snd_is_clkmaster()) { - ret = s3c24xx_snd_lrsync(); - if (ret) - goto exit_err; - } + if (!s3c24xx_snd_is_clkmaster()) + /* we ignore the return code, if it sync'd then fine, + * if it didn't sync, which happens after resume the + * first time when there was a live stream at suspend, + * just let it timeout, the stream picks up OK after + * that and LRCK is evidently working again. + */ + s3c24xx_snd_lrsync(); if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) s3c24xx_snd_rxctrl(1); -- cgit v1.2.3