ALSA: memalloc: Try dma_alloc_noncontiguous() at first

The latest fix for the non-contiguous memalloc helper changed the
allocation method for a non-IOMMU system to use only the fallback
allocator.  This should have worked, but it caused a problem sometimes
when too many non-contiguous pages are allocated that can't be treated
by HD-audio controller.

As a quirk workaround, go back to the original strategy: use
dma_alloc_noncontiguous() at first, and apply the fallback only when
it fails, but only for non-IOMMU case.

We'll need a better fix in the fallback code as well, but this
workaround should paper over most cases.

Fixes: 9736a32513 ("ALSA: memalloc: Don't fall back for SG-buffer with IOMMU")
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/CAHk-=wgSH5ubdvt76gNwa004ooZAEJL_1Q-Fyw5M2FDdqL==dg@mail.gmail.com
Link: https://lore.kernel.org/r/20221112084718.3305-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2022-11-12 09:47:18 +01:00
parent 9a5523f72b
commit 9d8e536d36

View File

@ -542,8 +542,10 @@ static void *snd_dma_noncontig_alloc(struct snd_dma_buffer *dmab, size_t size)
struct sg_table *sgt; struct sg_table *sgt;
void *p; void *p;
sgt = dma_alloc_noncontiguous(dmab->dev.dev, size, dmab->dev.dir,
DEFAULT_GFP, 0);
#ifdef CONFIG_SND_DMA_SGBUF #ifdef CONFIG_SND_DMA_SGBUF
if (!get_dma_ops(dmab->dev.dev)) { if (!sgt && !get_dma_ops(dmab->dev.dev)) {
if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG) if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG)
dmab->dev.type = SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK; dmab->dev.type = SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK;
else else
@ -551,9 +553,6 @@ static void *snd_dma_noncontig_alloc(struct snd_dma_buffer *dmab, size_t size)
return snd_dma_sg_fallback_alloc(dmab, size); return snd_dma_sg_fallback_alloc(dmab, size);
} }
#endif #endif
sgt = dma_alloc_noncontiguous(dmab->dev.dev, size, dmab->dev.dir,
DEFAULT_GFP, 0);
if (!sgt) if (!sgt)
return NULL; return NULL;