[ALSA] AMD Au1x00: fix DMA init/cleanup

Modules: MIPS AU1x00 driver

AMD Au1x00 ALSA driver causes kernel oops in au1000_init() by trying
to set DMA channel to -1 in yet unallocated audio streams. Here's the
patch that staightens up DMA init/cleanup code.

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 20 insertions, 13 deletions

diff --git a/sound/mips/au1x00.c b/sound/mips/au1x00.c
index e66b0144e3b5..961453b77fc9 100644
--- a/sound/mips/au1x00.c
+++ b/sound/mips/au1x00.c
@@ -612,14 +612,17 @@ snd_au1000_free(struct snd_card *card)
                 release_and_free_resource(au1000->ac97_res_port);
         }
 
-        if (au1000->stream[PLAYBACK]->dma >= 0)
-                free_au1000_dma(au1000->stream[PLAYBACK]->dma);
-
-        if (au1000->stream[CAPTURE]->dma >= 0)
-                free_au1000_dma(au1000->stream[CAPTURE]->dma);
+        if (au1000->stream[PLAYBACK]) {
+                if (au1000->stream[PLAYBACK]->dma >= 0)
+                        free_au1000_dma(au1000->stream[PLAYBACK]->dma);
+                kfree(au1000->stream[PLAYBACK]);
+        }
 
-        kfree(au1000->stream[PLAYBACK]);
-        kfree(au1000->stream[CAPTURE]);
+        if (au1000->stream[CAPTURE]) {
+                if (au1000->stream[CAPTURE]->dma >= 0)
+                        free_au1000_dma(au1000->stream[CAPTURE]->dma);
+                kfree(au1000->stream[CAPTURE]);
+        }
 }
 
 
@@ -638,15 +641,19 @@ au1000_init(void)
 
         card->private_free = snd_au1000_free;
         au1000 = card->private_data;
-        /* so that snd_au1000_free will work as intended */
         au1000->card = card;
-        au1000->stream[PLAYBACK]->dma = -1;
-        au1000->stream[CAPTURE]->dma = -1;
-        au1000->ac97_res_port = NULL;
+
         au1000->stream[PLAYBACK] = kmalloc(sizeof(struct audio_stream), GFP_KERNEL);
-        au1000->stream[CAPTURE] = kmalloc(sizeof(struct audio_stream), GFP_KERNEL);
+        au1000->stream[CAPTURE ] = kmalloc(sizeof(struct audio_stream), GFP_KERNEL);
+        /* so that snd_au1000_free will work as intended */
+        au1000->ac97_res_port = NULL;
+        if (au1000->stream[PLAYBACK])
+                au1000->stream[PLAYBACK]->dma = -1;
+        if (au1000->stream[CAPTURE ])
+                au1000->stream[CAPTURE ]->dma = -1;
+
         if (au1000->stream[PLAYBACK] == NULL ||
-            au1000->stream[CAPTURE] == NULL) {
+            au1000->stream[CAPTURE ] == NULL) {
                 snd_card_free(card);
                 return -ENOMEM;
         }