From: Russell King Date: Thu, 26 Nov 2009 12:31:15 +0000 (+0000) Subject: ARM: use flush_kernel_dcache_area() for dmabounce X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=f74f7e57ae9fa12b2951ae62ce3557799b318399;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git ARM: use flush_kernel_dcache_area() for dmabounce After copying data from the bounce buffer to the real buffer, use flush_kernel_dcache_page() to ensure that data is written back in manner coherent with future userspace mappings. Signed-off-by: Russell King --- diff --git a/arch/arm/common/dmabounce.c b/arch/arm/common/dmabounce.c index 5a375e5fef21..bc90364a96c7 100644 --- a/arch/arm/common/dmabounce.c +++ b/arch/arm/common/dmabounce.c @@ -308,15 +308,11 @@ static inline void unmap_single(struct device *dev, dma_addr_t dma_addr, memcpy(ptr, buf->safe, size); /* - * DMA buffers must have the same cache properties - * as if they were really used for DMA - which means - * data must be written back to RAM. Note that - * we don't use dmac_flush_range() here for the - * bidirectional case because we know the cache - * lines will be coherent with the data written. + * Since we may have written to a page cache page, + * we need to ensure that the data will be coherent + * with user mappings. */ - dmac_clean_range(ptr, ptr + size); - outer_clean_range(__pa(ptr), __pa(ptr) + size); + __cpuc_flush_kernel_dcache_area(ptr, size); } free_safe_buffer(dev->archdata.dmabounce, buf); }