am335x: 5.18.x: system stalling

[Yegor Yefremov]

Hi Ard,

On Thu, May 26, 2022 at 10:19 AM Ard Biesheuvel <ardb at kernel.org> wrote:
>
> On Thu, 26 May 2022 at 08:20, Tony Lindgren <tony at atomide.com> wrote:
> >
> > * Yegor Yefremov <yegorslists at googlemail.com> [220526 05:45]:
> > > On Tue, May 24, 2022 at 4:19 PM Tony Lindgren <tony at atomide.com> wrote:
> > > > Maybe also try with CONFIG_MUSB_PIO_ONLY=y to see if it makes things
> > > > better or worse :)
> > >
> > > PIO is always the last resort :-) And now it proves it again. With
> > > PIO_ONLY the system doesn't stall.
> >
> > OK great :) So it has something to do with drivers/dma/ti/cppi41.c, or
> > with drivers/usb/musb/cppi_dma.c or whatever the dma for am335x here
> > is. Or maybe there's something using stack for buffers being passed to
> > dma again that breaks with vmap stack.
> >
>
> In order to confirm this theory, could you please try rebuilding your
> kernel with CONFIG_VMAP_STACK disabled, and leave everything else as
> before?

I have disabled the CONFIG_VMAP_STACK option:

# zcat /proc/config.gz | grep VMAP_STACK
CONFIG_HAVE_ARCH_VMAP_STACK=y
# CONFIG_VMAP_STACK is not set

The system stalls.