> -----Original Message----- > From: Valkeinen, Tomi > Sent: Wednesday, January 08, 2014 7:44 PM > To: Tony Lindgren; Ivaylo Dimitrov > Cc: Hiremath, Vaibhav; linux-omap@xxxxxxxxxxxxxxx; linux-arm- > kernel@xxxxxxxxxxxxxxxxxxx; linux-fbdev@xxxxxxxxxxxxxxx > Subject: Re: [PATCH 1/2] ARM: omapfb: add coherent dma memory support > > On 2014-01-08 01:59, Tony Lindgren wrote: > > * Tomi Valkeinen <tomi.valkeinen@xxxxxx> [131230 05:21]: > >> 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 <tomi.valkeinen@xxxxxx> > >> Cc: Ivaylo Dimitrov <freemangordon@xxxxxx> > > > > Feel free to queue this along with the DSS patches: > > > > Acked-by: Tony Lindgren <tony@xxxxxxxxxxx> > > Thanks. > > This introduces new kernel boot parameter, and I haven't really had time to test > and think about this. If Ivaylo doesn't insist on this to be merged for 3.14, I'd > rather leave this for 3.15 as adding new parameter that we need to support > "forever" should be thought a bit more. > Tomi, I am seeing underflow issue on AM43x device if I use omapfb_vram argument. Did you see this on OMAP? I am using "omapfb_vram=10M@0xA0000000", and I believe it is correct way of usage. Thanks, Vaibhav > Tomi > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
