So many thanks!Vladimir. But why 720*480 succeeded?Its size is 2488320 byte, which exceeds 2M already. I have checked the CONSISTENT_DMA_SIZE of my arch.Its value is 14M, that should be enough.
any other suggestion? On Wed, 2008-05-07 at 09:31 +0200, Vladimir Pantelic wrote: > steven.zhang wrote: > > Hi, all. > > I am porting the davincifb driver to support 1280*720 resolution. > > As you know, I should alloc memory for different OSD windows. > > To support 1280*720 p, I do it as follows: > > > > #define DISP_XRES 1280 > > #define DISP_YRES 720 > > #define DISP_MEMY 740 > > #define VID0_FB_SIZE (round_32(DISP_XRES*16/8) * DISP_MEMY * > > TRIPLE_BUF) > > > > using dma_alloc_coherent() to allocate 5683200byte > > memory.However, it fails. > > when define DISP_XRES be 720 and DISP_YRES be 480, it succeeds. > > > > > > What can be the problems? dma_alloc_coherent() can not allocate 5683200 > > (about 5M) memory using for DMA? > > maybe this: > > http://kerneltrap.org/node/3600 > > what is your CONSISTENT_DMA_SIZE, default is: > > /linux/include/asm/memory.h: > #define CONSISTENT_DMA_SIZE SZ_2M > > but your arch could define another value. > > > > _______________________________________________ > Davinci-linux-open-source mailing list > [email protected] > http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source _______________________________________________ Davinci-linux-open-source mailing list [email protected] http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
