From 646ab160ff5e672838209dbd679d50af63fbd366 Mon Sep 17 00:00:00 2001 From: Harald Welte Date: Tue, 24 Jul 2007 12:49:39 +0200 Subject: [PATCH] [ALSA] s3c24xx-pcm: fix hw_params dma handling Since the PCM emulation can call multiple times to hw_setup(), but we can only once allocate/request the DMA channel, we have to handle this gracefully. Signed-off-by: Harald Welte Signed-off-by: Arnaud Patard Signed-off-by: Takashi Iwai Signed-off-by: Jaroslav Kysela --- sound/soc/s3c24xx/s3c24xx-pcm.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/sound/soc/s3c24xx/s3c24xx-pcm.c b/sound/soc/s3c24xx/s3c24xx-pcm.c index bfbdc3cbd43..4107a87d4de 100644 --- a/sound/soc/s3c24xx/s3c24xx-pcm.c +++ b/sound/soc/s3c24xx/s3c24xx-pcm.c @@ -158,18 +158,22 @@ static int s3c24xx_pcm_hw_params(struct snd_pcm_substream *substream, if (!dma) return 0; - /* prepare DMA */ - prtd->params = dma; + /* this may get called several times by oss emulation + * with different params -HW */ + if (prtd->params == NULL) { + /* prepare DMA */ + prtd->params = dma; - DBG("params %p, client %p, channel %d\n", prtd->params, - prtd->params->client, prtd->params->channel); + DBG("params %p, client %p, channel %d\n", prtd->params, + prtd->params->client, prtd->params->channel); - ret = s3c2410_dma_request(prtd->params->channel, - prtd->params->client, NULL); + ret = s3c2410_dma_request(prtd->params->channel, + prtd->params->client, NULL); - if (ret) { - DBG(KERN_ERR "failed to get dma channel\n"); - return ret; + if (ret) { + DBG(KERN_ERR "failed to get dma channel\n"); + return ret; + } } /* channel needs configuring for mem=>device, increment memory addr, -- 2.41.1