# HG changeset patch
# User fam@procyon
# Date 1167417628 18000
# Node ID db7345e709ceb94df2cce3ea8ea7d32cc83d789e
# Parent  4eae1a19406e9e14c38efdef7fb1bd603200485d
ASoC at91 - Fix NULL pointer dereference in at91_i2s_shutdown

at91_i2s_shutdown() depends on the snd_soc_cpu_dai dma_data field
being NULL if the substream's DMA parameters were not set up.

However, if a substream was started, then shutdown before the DMA
parameters were setup, the dma_data field would still contain the
value that was set for a previous substream, which pointed to an
invalid at91_pcm_dma_params structure.

The fix is to initialize the dma_data field to NULL when the
substream is started.

Signed-off-by: Frank Mandarino <fmandarino@endrelia.com>
Signed-off-by: Liam Girdwood <lg@opensource.wolfsonmicro.com>

diff -r 4eae1a19406e -r db7345e709ce soc/at91/at91-i2s.c
--- a/soc/at91/at91-i2s.c	Thu Dec 28 13:56:48 2006 +0100
+++ b/soc/at91/at91-i2s.c	Fri Dec 29 13:40:28 2006 -0500
@@ -295,6 +295,13 @@ static int at91_i2s_startup(struct snd_p
 	}
 	ssc_p->dir_mask |= dir_mask;
 	spin_unlock_irq(&ssc_p->lock);
+
+	/*
+	 * dma_data is not set until hw_params() is called and
+	 * shutdown() depends on this value being NULL if hw_params()
+	 * was not called.
+	 */
+	rtd->cpu_dai->dma_data = NULL;
 
 	return 0;
 }