ASoC: Fix NULL pointer dereference in __pxa2xx_pcm_hw_free
[linux-2.6.git] / sound / arm / devdma.c
1 /*
2  *  linux/sound/arm/devdma.c
3  *
4  *  Copyright (C) 2003-2004 Russell King, All rights reserved.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  *  ARM DMA shim for ALSA.
11  */
12 #include <linux/device.h>
13 #include <linux/dma-mapping.h>
14
15 #include <sound/core.h>
16 #include <sound/pcm.h>
17
18 #include "devdma.h"
19
20 void devdma_hw_free(struct device *dev, struct snd_pcm_substream *substream)
21 {
22         struct snd_pcm_runtime *runtime = substream->runtime;
23         struct snd_dma_buffer *buf = runtime->dma_buffer_p;
24
25         if (runtime->dma_area == NULL)
26                 return;
27
28         if (buf != &substream->dma_buffer) {
29                 dma_free_coherent(buf->dev.dev, buf->bytes, buf->area, buf->addr);
30                 kfree(runtime->dma_buffer_p);
31         }
32
33         snd_pcm_set_runtime_buffer(substream, NULL);
34 }
35
36 int devdma_hw_alloc(struct device *dev, struct snd_pcm_substream *substream, size_t size)
37 {
38         struct snd_pcm_runtime *runtime = substream->runtime;
39         struct snd_dma_buffer *buf = runtime->dma_buffer_p;
40         int ret = 0;
41
42         if (buf) {
43                 if (buf->bytes >= size)
44                         goto out;
45                 devdma_hw_free(dev, substream);
46         }
47
48         if (substream->dma_buffer.area != NULL && substream->dma_buffer.bytes >= size) {
49                 buf = &substream->dma_buffer;
50         } else {
51                 buf = kmalloc(sizeof(struct snd_dma_buffer), GFP_KERNEL);
52                 if (!buf)
53                         goto nomem;
54
55                 buf->dev.type = SNDRV_DMA_TYPE_DEV;
56                 buf->dev.dev = dev;
57                 buf->area = dma_alloc_coherent(dev, size, &buf->addr, GFP_KERNEL);
58                 buf->bytes = size;
59                 buf->private_data = NULL;
60
61                 if (!buf->area)
62                         goto free;
63         }
64         snd_pcm_set_runtime_buffer(substream, buf);
65         ret = 1;
66  out:
67         runtime->dma_bytes = size;
68         return ret;
69
70  free:
71         kfree(buf);
72  nomem:
73         return -ENOMEM;
74 }
75
76 int devdma_mmap(struct device *dev, struct snd_pcm_substream *substream, struct vm_area_struct *vma)
77 {
78         struct snd_pcm_runtime *runtime = substream->runtime;
79         return dma_mmap_coherent(dev, vma, runtime->dma_area, runtime->dma_addr, runtime->dma_bytes);
80 }