ASoC: PXA: Fix oops in __pxa2xx_pcm_prepare

pxa2xx_pcm_hw_free frees dma channel and sets prtd->dma_ch to -1,
but does not set prtd->params to NULL, so if pxa2xx_pcm_hw_params will
be called immediately, it leaves prtd->dma_ch initialized with -1,
and it results in oops in __pxa2xx_pcm_prepare. This bug is triggered
via SDL.

This patch adds check for prtd->dma_ch to __pxa2xx_pcm_prepare and
cleans prtd->params, so now it works properly.

Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --git a/sound/arm/pxa2xx-pcm-lib.c b/sound/arm/pxa2xx-pcm-lib.c
index 8808b82..76e0d56 100644 (file)
--- a/sound/arm/pxa2xx-pcm-lib.c
+++ b/sound/arm/pxa2xx-pcm-lib.c
@@ -140,6 +140,9 @@ int __pxa2xx_pcm_prepare(struct snd_pcm_substream *substream)
        if (!prtd || !prtd->params)
                return 0;
 
+       if (prtd->dma_ch == -1)
+               return -EINVAL;
+
        DCSR(prtd->dma_ch) &= ~DCSR_RUN;
        DCSR(prtd->dma_ch) = 0;
        DCMD(prtd->dma_ch) = 0;

diff --git a/sound/soc/pxa/pxa2xx-pcm.c b/sound/soc/pxa/pxa2xx-pcm.c
index 02fb664..2ce0b2d 100644 (file)
--- a/sound/soc/pxa/pxa2xx-pcm.c
+++ b/sound/soc/pxa/pxa2xx-pcm.c
@@ -65,6 +65,7 @@ static int pxa2xx_pcm_hw_free(struct snd_pcm_substream *substream)
        if (prtd->dma_ch >= 0) {
                pxa_free_dma(prtd->dma_ch);
                prtd->dma_ch = -1;
+               prtd->params = NULL;
        }
 
        return 0;