[alsa-devel] [PATCH] MIPS: Fixups of ALSA memory maps
Wu Zhangjin
wuzhangjin at gmail.com
Mon Nov 16 17:48:14 CET 2009
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
------------------------
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 at gmail.com>
Signed-off-by: Wu Zhangjin <wuzj at 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:
--
1.6.2.1
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