Re: remoteproc DMA API abuse status

From: Mathieu Poirier
Date: Mon Jun 28 2021 - 16:14:36 EST


On Fri, Jun 25, 2021 at 09:27:09AM +0200, Arnaud POULIQUEN wrote:
> Hello Mathieu,
>
> On 6/24/21 9:35 PM, Mathieu Poirier wrote:
> > Good day Christoph,
> >
> > On Wed, Jun 23, 2021 at 03:43:07PM +0200, Christoph Hellwig wrote:
> >> Hi remoteproc maintainers,
> >>
> >> did you make any progress to get remoteproc out of creating fake
> >> devices that fake their dma ops status and the abuse of
> >> dma_declare_coherent_memory in removeproc_virtio? I remember we had
> >> a discussion on this a long time ago, and there was an unfinished
> >> patchset to change the memory pool handling. What happened to all that?
> >
> > I believe the conversation and patchset you are referring to are pre-dating my
> > time in this subsystem. To make sure I am looking at the right thing, can you
> > (or anyone else) point me to that discussion and related patches?
>
> 2 references:
>
> 1)Previous discussion thread on the topic:
>
> https://patchwork.kernel.org/project/linux-remoteproc/patch/AOKowLclCbOCKxyiJ71WeNyuAAj2q8EUtxrXbyky5E@xxxxxxxxxxxxxxxxxxxx/
>

I remember that one. Glad to see there wasn't anything else before that.

> 2) My patchset related to the refactoring of remoteproc virtio which tries to
> address the point by creating a remoteproc platform driver and declaring a
> virtio subnode in the device tree remoteproc node.
>
> https://lkml.org/lkml/2020/4/16/1817
>

I thought your current work on refactoring the rpmsg_char driver was part of the
early steps on the way to splitting that patchset up...

> No time yet on my side to come back on the patchset :(
>

I know the feeling.

Thanks for the info,
Mathieu