[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>

diff --git a/sound/mips/au1x00.c b/sound/mips/au1x00.c
index e66b014..961453b 100644 (file)
--- 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;
        }