diff options
| author | Takashi Iwai <tiwai@suse.de> | 2008-05-09 08:06:55 +0200 |
|---|---|---|
| committer | Jesse Barnes <jbarnes@virtuousgeek.org> | 2008-05-13 09:51:53 -0700 |
| commit | 4a367f3a9dbf2e7ffcee4702203479809236ee6e (patch) | |
| tree | 8481ac4f6d916f7d4322d3cee235131f537819c8 /arch | |
| parent | 21e2b0a5efb3a01de58e7cb630f2eb70894da352 (diff) | |
| download | linux-4a367f3a9dbf2e7ffcee4702203479809236ee6e.tar.bz2 | |
x86/PCI: fix broken ISA DMA
Rene Herman reported:
> commit 8779f2fc3b84ebb6c5181fb13d702e9944c16069
>
> "x86: don't try to allocate from DMA zone at first"
>
> breaks all of ISA DMA. Or all of ALSA ISA DMA at least. All
> ISA soundcards are silent following that commit -- no error
> messages, everything appears fine, just silence.
That patch is buggy. We had an implicit assumption that
dev = NULL for ISA devices that require 24bit DMA.
The recent work on x86 dma_alloc_coherent() breaks the ISA DMA buffer
allocation, which is represented by "dev = NULL" and requires 24bit
DMA implicitly.
Bisected-by: Rene Herman <rene.herman@keyaccess.nl>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/pci-dma.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c index 0c37f16b6950..c5ef1af8e79d 100644 --- a/arch/x86/kernel/pci-dma.c +++ b/arch/x86/kernel/pci-dma.c @@ -385,11 +385,13 @@ dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, if (dma_alloc_from_coherent_mem(dev, size, dma_handle, &memory)) return memory; - if (!dev) + if (!dev) { dev = &fallback_dev; + gfp |= GFP_DMA; + } dma_mask = dev->coherent_dma_mask; if (dma_mask == 0) - dma_mask = DMA_32BIT_MASK; + dma_mask = (gfp & GFP_DMA) ? DMA_24BIT_MASK : DMA_32BIT_MASK; /* Device not DMA able */ if (dev->dma_mask == NULL) @@ -403,7 +405,7 @@ dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, larger than 16MB and in this case we have a chance of finding fitting memory in the next higher zone first. If not retry with true GFP_DMA. -AK */ - if (dma_mask <= DMA_32BIT_MASK) + if (dma_mask <= DMA_32BIT_MASK && !(gfp & GFP_DMA)) gfp |= GFP_DMA32; #endif |