am335x: 5.18.x: system stalling

[Ard Biesheuvel]

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?