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authorTakashi Iwai <tiwai@suse.de>2008-05-12 15:43:30 +0200
committerIngo Molnar <mingo@elte.hu>2008-05-12 21:27:50 +0200
commit8965eb19386fdf5ccd0ef8b02593eb8560aa3416 (patch)
tree8107a8db856d7b02b8b4d7bb88e53db1df8344ef /arch/x86/kernel
parent492c2e476eac010962850006c49df326919b284c (diff)
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> Tested-by: Rene Herman <rene.herman@keyaccess.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/pci-dma.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index 0c37f16b695..c5ef1af8e79 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