From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ivaylo Dimitrov Date: Sun, 05 Jan 2014 14:16:54 +0000 Subject: Re: [PATCH 1/2] ARM: omapfb: add coherent dma memory support Message-Id: <52C96956.7040803@gmail.com> List-Id: References: <1388409550-10720-1-git-send-email-tomi.valkeinen@ti.com> <1388409550-10720-2-git-send-email-tomi.valkeinen@ti.com> In-Reply-To: <1388409550-10720-2-git-send-email-tomi.valkeinen@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org On 30.12.2013 15:19, Tomi Valkeinen wrote: > The omapfb driver uses dma_alloc to reserve memory for the framebuffers. > However, on some use cases, even when CMA is in use, it's quite probable > that omapfb fails to allocate the fb, either due to not enough free dma > memory, fragmented dma memory, or CMA failing to make enough contiguous > space. > > This patch adds a kernel cmdline parameter 'omapfb_vram' which can be > used to give the size of a memory area reserved exclusively for omapfb, > and optionally a physical address where the memory area is reserved. > > The memory area is reserved with memblock, and assigned to omapfb with > dma_declare_coherent_memory. The dma_alloc function will first try to > allocate the fb from the coherent memory area, and if that fails, it'll > use the normal method of allocation. > > Signed-off-by: Tomi Valkeinen > Cc: Ivaylo Dimitrov > --- > arch/arm/mach-omap2/common.c | 1 + > arch/arm/mach-omap2/common.h | 2 ++ > arch/arm/mach-omap2/fb.c | 77 +++++++++++++++++++++++++++++++++++++++++++- > 3 files changed, 79 insertions(+), 1 deletion(-) > Tested on Nokia N900 with Maemo5 and linux 3.13-rc6