Hi, All
Seems this is MIPS specific, but it's not that easy to move this patch into the arch/mips part, So, any better solution?
Thanks & Regards, Wu Zhangjin
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The user application mmap audio dma regions must be dma-coherent. This patch fix it.
Without this patch, artsd will fail on boot, and mplayer will exit with "Segmentation fault". (this happens on YeeLoong netbook, fuloong2f mini pc with snd_cs5535 audio card)
This is originally from the to-mips branch of http://dev.lemote.com/code/linux_loongson, and contributed by Yanhua from Lemote Inc.
Reported-by: qiaochong qiaochong@gmail.com Signed-off-by: Wu Zhangjin wuzj@lemote.com --- sound/core/pcm_native.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index ab73edf..2779b9a 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -3087,7 +3087,11 @@ static int snd_pcm_mmap_data_fault(struct vm_area_struct *area, return VM_FAULT_SIGBUS; } else { vaddr = runtime->dma_area + offset; +#if defined(__mips__) && defined(CONFIG_DMA_NONCOHERENT) + page = virt_to_page(CAC_ADDR(vaddr)); +#else page = virt_to_page(vaddr); +#endif } get_page(page); vmf->page = page; @@ -3202,6 +3206,11 @@ static int snd_pcm_mmap(struct file *file, struct vm_area_struct *area) if (PCM_RUNTIME_CHECK(substream)) return -ENXIO;
+#if defined(__mips__) && defined(CONFIG_DMA_NONCOHERENT) + /* all mmap using uncached mode */ + area->vm_page_prot = pgprot_noncached(area->vm_page_prot); + area->vm_flags |= (VM_RESERVED | VM_IO); +#endif offset = area->vm_pgoff << PAGE_SHIFT; switch (offset) { case SNDRV_PCM_MMAP_OFFSET_STATUS: