On Mon, Aug 20, 2018 at 4:17 PM Mikulas Patocka <mpatocka@xxxxxxxxxx> wrote:
> On Sun, 19 Aug 2018, okaya@xxxxxxxxxxxxxx wrote:
>
> > +my new email
> >
> > On 2018-08-18 19:03, Arnd Bergmann wrote:
> > > On Sat, Aug 18, 2018 at 12:05 AM Maciej W. Rozycki <macro@xxxxxxxxxxxxxx>
> > I think we need to identify the driver that is failing.
>
> It also may be some timing issue.
>
> I observed that not every kernel with the patch
> 92d7223a74235054f2aa7227d207d9c57f84dca0 fails, some of them get stuck
> only at boot, some get stuck only at shutdown, some not at all. Although
> all the kernels with this patch reverted work.
>
> So the patch may have uncovered some timing problem somewhere.
>
> x86 has the function io_delay that injects delays between I/O accesses for
> hardware that needs it - does alpha have something like this?
The I/O delay would be very low on my list of possible root causes
for this, hardly any hardware at all relies on it, and all uses I see
are related to outb(), which you've already shown not to be the problem
with my test patch.
Arnd
