Sorry, a typo was in this patch. The fixed version is below.
FYI, the patchset is found in sound git tree topic/pcm-dma-fix branch: git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6.git topic/pcm-dma-fix
thanks,
Takashi
From bc01f9e365d3afc041ab2c296107728c56410f8f Mon Sep 17 00:00:00 2001 From: Takashi Iwai tiwai@suse.de Date: Thu, 26 Nov 2009 15:04:24 +0100 Subject: [PATCH] ALSA: pcm - fix page conversion on non-coherent PPC arch
The non-cohernet PPC arch doesn't give the correct address by a simple virt_to_page() for pages allocated via dma_alloc_coherent(). This patch adds a hack to fix the conversion similarly like MIPS.
Note that this doesn't fix perfectly: the pages should be marked with proper pgprot value. This will be done in a future implementation like the conversion to dma_mmap_coherent().
Signed-off-by: Takashi Iwai tiwai@suse.de --- sound/core/pcm_native.c | 10 ++++++++++ 1 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index e48c5f6..29ab46a 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -3070,6 +3070,16 @@ snd_pcm_default_page_ops(struct snd_pcm_substream *substream, unsigned long ofs) if (substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV) return virt_to_page(CAC_ADDR(vaddr)); #endif +#if defined(CONFIG_PPC32) && defined(CONFIG_NOT_COHERENT_CACHE) + if (substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV) { + dma_addr_t addr = substream->runtime->dma_addr + ofs; + addr -= get_dma_offset(substream->dma_buffer.dev.dev); + /* assume dma_handle set via pfn_to_phys() in + * mm/dma-noncoherent.c + */ + return pfn_to_page(addr >> PAGE_SHIFT); + } +#endif return virt_to_page(vaddr); }