Messages in this thread | | | Date | Mon, 1 Oct 2012 09:56:03 -0400 | From | Matt Porter <> | Subject | Re: [PATCH v2 4/7] ARM: davinci: Add support for an L3RAM gen_pool |
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On Mon, Oct 01, 2012 at 08:32:42AM -0400, Matt Porter wrote: > On Mon, Oct 01, 2012 at 05:34:02PM +0530, Sekhar Nori wrote: > > Hi Matt, > > > > On 9/29/2012 1:07 AM, Matt Porter wrote: > > > L3RAM (shared SRAM) is needed for use by several drivers. > > > This creates a genalloc pool and a hook for the platform code > > > to provide the struct gen_pool * in platform data. > > > > > > Signed-off-by: Matt Porter <mporter@ti.com> > > > > I am not sure if any of the DaVinci devices have a need to allocate from > > *both* ARM RAM and shared RAM. Shared RAM is not present on all DaVinci > > devices AFAIR, and on DA850, there is just 8KB ARM RAM so I am not sure > > if there is much point in trying to allocate from there. > > > > Can you instead see if Ben's earlier patch[1] to use shared RAM for SRAM > > allocation on DA850 makes sense for your case? If yes, can you repost > > with Ben's patch included in your series instead of this patch? I would > > prefer that over creating a new pool for shared RAM. > > Hrm, I did look at Ben's earlier patch. The reason I added a separate > pool mostly was so I didn't have to touch the PM code at all. That can > continue using the private SRAM API with the ARM RAM as it is now. The > idea here was to allow that to be separate since no other bus masters > can access the ARM RAM anyway and do something that didn't require > regression testing PM. Also, I figured there's really no reason to use > even a tiny bit of the shared SRAM on PM if we have that ARM RAM there > and working fine for that use case. > > The other thing is that Ben's patch needs to be rewritten to at least > have the hook I added so we can provide the gen_pool in platform data. > If you prefer this path still, I can add the needed hook on top of his > original patch. Ultimately, I only *need* genalloc support for the > shared sram so I can remove the private SRAM API from uio_pruss...so I'm > happy with any way to get at it. > > Oh, and to be honest...it's not just for uio_pruss, but also to cleanly > remove the private SRAM API usage from the davinci ASoC driver too.
[and replying to myself :)]
Looking at the older parts (DM355/365/DM64xx) in more detail now, I see that to get rid of SRAM API in davinci ASoC, we'll have a similar hook to get the local ARM RAM gen_pool pointer necessary to support ping-pong to that pool since that's able to be accessed from EDMA on those parts. Ultimately, the approach is the same, it's just a matter of if we want to fully leverage both SRAM pools on DA850 and friends.
-Matt
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