On Thu, Nov 06, 2014 at 05:35:40PM +0800, Kuankuan.Yang wrote:
> I'm working on Designware hdmi-audio, also add it as a standard ALSA device.
> Before I saw this email, I also planed to submit my patchs to upsteam.
> I'm very grateful if you can email those patchs to us.

I've attached the set of patches - they're part of a much bigger patch
set for supporting the Cubox-i in mainline, but should apply cleanly.
They're against a 3.17 base rather than 3.18-rc, but I do have these
rebased as 3.18-rc2 based patches too.

I've been waiting for imx-drm to move out of drivers/staging before
deciding where they should live - there seems to be no good place in the
sound/ subtree to place these (sound/soc is not the right place.)

They're being used not only with the SolidRun Cubox-i and Hummingboard,
but also the Novena project too.

One thing the audio part does not yet support is using SDMA on iMX6 to
feed updates to the audio DMA, so this driver should work with other
non-iMX6 SDMA.

Patches 21 to 23 are various attempts to try and fix a problem I've
noticed only on certain iMX6 SoCs (two different revisions of the DW IP
are used in iMX6 depending on whether it's the solo/dual-lite parts, or
the dual/quad parts.)  Inspite of the published errata, I found that the
given workarounds had no useful effect on the problem, and like most
bought-in IP, it's extremely difficult to resolve these kinds of issues
from an open source perspective without having commercial links with
manufacturers to gain access to internal documentation and/or support.

The CEC bits provide a mostly compatible interface with the current FSL
iMX BSP trees, but with a different structure to it, and hopefully less
buggily than the FSL driver.  There has been an effort to add support
for the FSL interface to libcec, but when I've looked at the library,
I've never been impressed by the code, nor by the authors handling of
anything but a clean transmission (which IMHO makes the whole thing
unsafe, especially if you have multiple devices on the CEC bus, you
need the logical ID arbitration to work properly.)

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