RE: [PATCH v2] remoteproc: copy parent dma_pfn_offset for vdev

[Loic PALLARDY]

> -----Original Message-----
> From: Christoph Hellwig <hch@xxxxxxxxxxxxx>
> Sent: vendredi 19 juillet 2019 08:33
> To: Loic PALLARDY <loic.pallardy@xxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>; Clement Leger
> <cleger@xxxxxxxxx>; Ohad Ben-Cohen <ohad@xxxxxxxxxx>; Bjorn
> Andersson <bjorn.andersson@xxxxxxxxxx>; linux-
> remoteproc@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v2] remoteproc: copy parent dma_pfn_offset for vdev
> 
> On Mon, Jul 08, 2019 at 11:45:46AM -0700, Christoph Hellwig wrote:
> > > But that's breaking legacy as all platforms will have to add a virtio device
> node in
> > > their DT file...
> > >
> > > Is it aligned with your view ?
> >
> > Yes, that is how I'd assume it works.  But given that until recently
> > you did now have these subdevices for dma coherent purposes we can't
> > really break anything older than that, so I might still be missing
> > something.
> 
> Any chance we could expedite this?  remoteproc is the only driver
> inheriting dma ops to subdevices, and the only one using
> dma_declare_coherent_memory.  I'd really like to clean this mess up
> rather sooner than later.

Ongoing...
Two topics to clean up:
- Sub device creation and DMA ops inheritance --> need to use platform_device or device tree
- dma_declare_coherent_memory use --> it has been introduced to support internal memories declared via reg field.
I propose to migrate existing drivers on reserved memory usage and so remove dma_declare_coherent call from remoteproc core.