Hi, Ralf and Takashi Seems Takashi have sent the MIPS specific dma_mmap_coherent() at 18 Aug 2008: http://www.linux-mips.org/archives/linux-mips/2008-08/msg00178.html But that patch have not been accepted since it was not suitable to all of the MIPS variants. Without that patch, the ALSA output will be broken in some of the MIPS variants, can we make the implementation in the above url be weak, then the particular MIPS variants can override it with their own versions but the common MIPS variants can share it to fix the ALSA problem? I have attached a change of the above patch, which is applicable to the linux-2.6.33 and linux-2.6.34-rcX and I have tested it on my YeeLoong netbook, the following command function well with it. $ mplayer -ao alsa file.mp3 but without it, the ALSA output is broken. Regards, Wu Zhangjin
>From a6ee304febbd609d2936dd5b33a16482ef224c97 Mon Sep 17 00:00:00 2001 From: Wu Zhangjin <wuzhangjin@xxxxxxxxx> Date: Sun, 11 Apr 2010 03:58:13 +0800 Subject: [PATCH] MIPS: Implement dma_mmap_coherent() for ALSA audio output A lazy version of dma_mmap_coherent() implementation for MIPS. Without this patch, the ALSA sound output of MIPS is broken: $ mplayer -ao alsa file.mp3 (This patch was sent out by Takashi Iwai at '18 Aug 2008' but not have been applied yet for it is not suitable for all MIPS variants. If you need more info, please access: http://www.linux-mips.org/archives/linux-mips/2008-08/msg00178.html) Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> --- arch/mips/include/asm/dma-mapping.h | 4 ++++ arch/mips/mm/dma-default.c | 13 +++++++++++++ 2 files changed, 17 insertions(+), 0 deletions(-) diff --git a/arch/mips/include/asm/dma-mapping.h b/arch/mips/include/asm/dma-mapping.h index 664ba53..c39bfdf 100644 --- a/arch/mips/include/asm/dma-mapping.h +++ b/arch/mips/include/asm/dma-mapping.h @@ -74,4 +74,8 @@ extern int dma_is_consistent(struct device *dev, dma_addr_t dma_addr); extern void dma_cache_sync(struct device *dev, void *vaddr, size_t size, enum dma_data_direction direction); +#define ARCH_HAS_DMA_MMAP_COHERENT +extern int dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma, + void *cpu_addr, dma_addr_t handle, size_t size); + #endif /* _ASM_DMA_MAPPING_H */ diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c index 9547bc0..8388428 100644 --- a/arch/mips/mm/dma-default.c +++ b/arch/mips/mm/dma-default.c @@ -375,3 +375,16 @@ void dma_cache_sync(struct device *dev, void *vaddr, size_t size, } EXPORT_SYMBOL(dma_cache_sync); + +int __weak dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma, + void *cpu_addr, dma_addr_t handle, size_t size) +{ + struct page *pg; + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); + cpu_addr = (void *)dma_addr_to_virt(dev, handle); + pg = virt_to_page(cpu_addr); + return remap_pfn_range(vma, vma->vm_start, + page_to_pfn(pg) + vma->vm_pgoff, + size, vma->vm_page_prot); +} +EXPORT_SYMBOL(dma_mmap_coherent); -- 1.7.0
