DMA_TO_DEVICE synchronisation must be done after the last modification of the memory region by the software and before it is handed off to the device.
Signed-off-by: Hui Tang tanghui20@huawei.com --- drivers/video/fbdev/grvga.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/video/fbdev/grvga.c b/drivers/video/fbdev/grvga.c index 24818b2..25ae9ef 100644 --- a/drivers/video/fbdev/grvga.c +++ b/drivers/video/fbdev/grvga.c @@ -435,6 +435,8 @@ static int grvga_probe(struct platform_device *dev) retval = -ENOMEM; goto dealloc_cmap; } + + memset((unsigned long *) virtual_start, 0, grvga_mem_size); } else { /* Allocate frambuffer memory */
unsigned long page; @@ -449,6 +451,7 @@ static int grvga_probe(struct platform_device *dev) goto dealloc_cmap; }
+ memset((unsigned long *) virtual_start, 0, grvga_mem_size); physical_start = dma_map_single(&dev->dev, (void *)virtual_start, grvga_mem_size, DMA_TO_DEVICE);
/* Set page reserved so that mmap will work. This is necessary @@ -463,8 +466,6 @@ static int grvga_probe(struct platform_device *dev) par->fb_alloced = 1; }
- memset((unsigned long *) virtual_start, 0, grvga_mem_size); - info->screen_base = (char __iomem *) virtual_start; info->fix.smem_start = physical_start; info->fix.smem_len = grvga_mem_size;