Re: [PATCH] rpmsg_ns: Work around TI non-standard message

[Richard Weinberger <richard@sigma-star.at>]

Mathieu,

Am Dienstag, 15. Oktober 2024, 18:48:08 CEST schrieb Mathieu Poirier:
> Good morning Richard,
> 
> On Fri, Oct 11, 2024 at 02:39:22PM +0200, Richard Weinberger wrote:
> > Texas Instruments ships a patch in their vendor kernels,
> > which adds a new NS message that includes a description field.
> > While TI is free to do whatever they want in their copy of the kernel,
> > it becomes a mess when people switch to a mainline kernel and want
> > to use their existing DSP programs with it.
> 
> I suspect there is a lot more things to change when going from downstream to a
> mainline kernel.

Not really.
I had to revert c6aed238b7a9b ("remoteproc: modify vring allocation to rely on centralized carveout allocator")
because the DSP has a sub-optimal resource table, and this workaround.
With that the DSP program worked as-is on kernel 6.6.
Downstream was 4.19 TI.

> > 
> > To make it easier to migrate to a mainline kernel,
> > let's make the kernel aware of their non-standard extension but
> > briefly ignore the description field.
> 
> In my opinion the real fix here is to get TI to use the standard message
> announcement structure.  The ->desc field doesn't seem to be that useful since
> it gets discarted.

This is for the future, the goal of my patch is helping people to
get existing DSP programs work with mainline.
Not everyone can or want to rebuild theirs DSP programs when moving to a mainline
kernel.

Thanks,
//richard

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