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

Takashi Iwai
2020-06-09T11:46:50Z

On Tue, 09 Jun 2020 13:40:59 +0200,
Christoph Hellwig wrote:
>
> On Tue, Jun 09, 2020 at 01:38:46PM +0200, Takashi Iwai wrote:
> > 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.
>
> So it looks like we could just turn off CONFIG_SND_DMA_SGBUF and
> be done with it? After all this works on other architectures
> just fine..

Yes, for the sound stuff, something below should make things working.
But it means that we'll lose the SG-buffer allocation and the
allocation of large buffers might fail on some machines.

Takashi

--- a/sound/core/Kconfig
+++ b/sound/core/Kconfig
@@ -192,6 +192,6 @@ config SND_VMASTER

config SND_DMA_SGBUF
def_bool y
- depends on X86
+ depends on X86 && BROKEN

source "sound/core/seq/Kconfig"