xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

DMA-API: sound: fix dma mask handling in a lot of drivers

Browse Source 
This code sequence is unsafe in modules:

static u64 mask = DMA_BIT_MASK(something);
...
	if (!dev->dma_mask)
		dev->dma_mask = &mask;

as if a module is reloaded, the mask will be pointing at the original
module's mask address, and this can lead to oopses.  Moreover, they
all follow this with:

	if (!dev->coherent_dma_mask)
		dev->coherent_dma_mask = mask;

where 'mask' is the same value as the statically defined mask, and this
bypasses the architecture's check on whether the DMA mask is possible.

Fix these issues by using the new dma_coerce_coherent_and_mask()
function.

Acked-by: Mark Brown <broonie@linaro.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King
2013-06-27 12:53:37 +01:00
parent fa6a8d6d65
commit c9bd5e690a
16 changed files with 61 additions and 104 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
sound/arm/pxa2xx-pcm.c
View File

@@ -11,6 +11,7 @@
*/
#include <linux/module.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <sound/core.h>
@@ -83,8 +84,6 @@ static struct snd_pcm_ops pxa2xx_pcm_ops = {
.mmap = pxa2xx_pcm_mmap,
};
static u64 pxa2xx_pcm_dmamask = 0xffffffff;
int pxa2xx_pcm_new(struct snd_card *card, struct pxa2xx_pcm_client *client,
struct snd_pcm **rpcm)
{
@@ -100,10 +99,9 @@ int pxa2xx_pcm_new(struct snd_card *card, struct pxa2xx_pcm_client *client,
pcm->private_data = client;
pcm->private_free = pxa2xx_pcm_free_dma_buffers;
if (!card->dev->dma_mask)
card->dev->dma_mask = &pxa2xx_pcm_dmamask;
if (!card->dev->coherent_dma_mask)
card->dev->coherent_dma_mask = 0xffffffff;
ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
if (ret)
goto out;
if (play) {
int stream = SNDRV_PCM_STREAM_PLAYBACK;