[PATCH] dma: imx-sdma: Add ROM script addresses to driver

[Sascha Hauer]

On Thu, Aug 29, 2013 at 12:23:02PM -0500, Matt Sealey wrote:
> On Tue, Aug 20, 2013 at 10:02 AM, Sascha Hauer <s.hauer at pengutronix.de> wrote:
> >
> >> What I'd really like to see is the "waiting on a firmware that doesn't
> >> exist when there is a working ROM version of those scripts in the SoC"
> >
> > Then this patch is for you. This is exactly what the patch solves.
> 
> Only by changing the device tree and not specifying a firmware
> filename. The driver probes, knows about ROM script addresses as per
> your patch, tries to load a new file from disk; same hang. What you
> have now is a way to use a potentially buggy script with several
> functions missing (ROM script isn't as full-featured as the file-based
> one on some chips) or a hang on boot if you misplaced a firmware which
> is notoriously hard to get hold of..
> 
> How do we resolve this except to load the firmware pre-Linux (or put
> the firmware in the tree, argh) and describe the loaded firmware and
> offsets? Once it's in the internal SDMA code RAM all the versioning
> and headers go away..

This seems quite academic. In theory there are many fancy things you can
do with the SDMA engine. In practice it is only used for audio. This
usecase is covered well by the current code and now even without loading
additional firmware. If you have the need for improvements feel free to
send patches.

Sascha

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