Hi Tony, On 2012-11-13 00:50, Tony Lindgren wrote: > * Tomi Valkeinen <tomi.valkeinen@xxxxxx> [121112 02:27]: >> Hi, >> >> This series changes omapfb to use standard dma_alloc funcs instead of omap >> specific vram allocator. This let's us remove the omap vram allocator, making >> omapfb platform independent. >> >> However, note that using standard dma funcs causes the following downsides: >> >> 1) dma_alloc_attrs doesn't let us allocate at certain physical address. >> However, this should not be a problem as this feature of vram allocator >> is only used when reserving the framebuffer that was initialized by the >> bootloader, and we don't currently support "passing" a framebuffer from >> the bootloader to the kernel anyway. >> >> 2) dma_alloc_attrs, as of now, always ioremaps the allocated area, and >> we don't need the ioremap when using VRFB. This patch uses >> DMA_ATTR_NO_KERNEL_MAPPING for the allocation, but the flag is currently >> not operational. >> >> 3) OMAPFB_GET_VRAM_INFO ioctl cannot return real values anymore. I >> changed the ioctl to return 64M for all the values, which, I hope, the >> applications will interpret as "there's enough vram". >> >> 4) "vram" kernel parameter to define how much ram to reserve for video use no >> longer works. The user needs to enable CMA and use "cma" parameter. > > Great, thanks for fixing these. Could you please queue these into > a separate branch against v3.7-rc5 that I can also merge into > omap-for-v3.8/cleanup-headers-prepare-multiplatform-v3? Should we enable CMA by default in omap2plus_defconfig? And perhaps on omap1 also? I have to say I don't know the details of the dma allocation, but afaik there are no drawbacks with CMA. Although it is still marked EXPERIMENTAL in the kconfig... Tomi
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