On 25/04/2022 15:28, Peter Ujfalusi wrote:
> From: Peter Ujfalusi <peter.ujfalusi@xxxxxxxxx>
>
> If the dma_alloc_noncontiguous() fails in snd_dma_noncontig_alloc() we are
> taking a fallback path which should be taken into account on the free path
> since the way to free the two type of allocations are not the same.
>
> Fixes: 925ca893b4a6 ("ALSA: memalloc: Add fallback SG-buffer allocations for x86")
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxxxxx>
> ---
> Hi Takashi,
>
> I'm not sure about thisa as I can not get my systems to use the fallback, but in
> theory this shiuld be done, no?
RIght, this is not needed as on the free path the callback is picked
based on the dmab->dev.type, so it should be picking the correct free
after all.
Please this patch.
> Since you have introduced the fallback, I believe there are cases when it is
> taken and it might be related to some strange memory allocation errors happening
> in SOF during firmware loading, like:
> https://github.com/thesofproject/linux/issues/3609
> https://github.com/thesofproject/linux/issues/3584
> https://github.com/thesofproject/linux/issues/3530
Still these reports are real and somehow they are pointing to dma
allocation issues.
Hrm, the fallback got backported to 5.17.4, so it might have been fixed
already?
> Regards,
> Peter
>
> sound/core/memalloc.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c
> index 15dc7160ba34..475fd38a4a48 100644
> --- a/sound/core/memalloc.c
> +++ b/sound/core/memalloc.c
> @@ -537,6 +537,13 @@ static void *snd_dma_noncontig_alloc(struct snd_dma_buffer *dmab, size_t size)
>
> static void snd_dma_noncontig_free(struct snd_dma_buffer *dmab)
> {
> + if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK ||
> + dmab->dev.type == SNDRV_DMA_TYPE_DEV_SG_FALLBACK) {
> + /* The allocation is done with a fallback, use the matching free */
> + snd_dma_sg_fallback_free(dmab);
> + return;
> + }
> +
> dma_vunmap_noncontiguous(dmab->dev.dev, dmab->area);
> dma_free_noncontiguous(dmab->dev.dev, dmab->bytes, dmab->private_data,
> dmab->dev.dir);
--
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