Re: next-0519 on thinkpad x60: sound related? window manager crash

From: Takashi Iwai
Date: Tue Jun 09 2020 - 07:38:50 EST


On Tue, 09 Jun 2020 13:31:23 +0200,
Christoph Hellwig wrote:
>
> On Tue, Jun 09, 2020 at 11:31:20AM +0200, Takashi Iwai wrote:
> > > > How would be a proper way to get the virtually mapped SG-buffer pages
> > > > with coherent memory? (Also allowing user-space mmap, too)
> > >
> > > dma_mmap_coherent / dma_mmap_attrs for userspace. We don't really
> > > have a good way for kernel space mappings.
> >
> > And that's the missing piece right now... :-<
>
> Can you point me to the relevant places (allocation and vmap mostly)
> so that I can take a look at how to fix this mess?

Found in sound/core/sgbuf.c. It's specific to x86.
Also, for V4L, drivers/media/v4l2-core/videobuf-dma-sg.c.


thanks,

Takashi