Re: [PATCH v6] amba: Remove deferred device addition

[Guenter Roeck]

On 8/9/22 17:42, Saravana Kannan wrote:
> On Tue, Aug 9, 2022 at 3:30 AM Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
> > Hi,
> >
> > On Wed, Jul 27, 2022 at 11:19:35AM -0700, Saravana Kannan wrote:
> > > The uevents generated for an amba device need PID and CID information
> > > that's available only when the amba device is powered on, clocked and
> > > out of reset. So, if those resources aren't available, the information
> > > can't be read to generate the uevents. To workaround this requirement,
> > > if the resources weren't available, the device addition was deferred and
> > > retried periodically.
> > ...
> >
> > This patch results in a large number of crashes in various qemu
> > emulations. Crash and bisect logs below. Reverting this patch
> > fixes the problem.
>
> Hey Guenter,
>
> Thanks for the report. I'm kinda surprised because I had a pl011 probe
> successfully in my local testing.

Maybe it only happens with qemu emulations, or with certain configurations.

> I'm wondering if you are having an interaction with some other changes I made.
> Can you try pulling this series in and see if it helps?
>
> https://lore.kernel.org/lkml/20220727185012.3255200-1-saravanak@xxxxxxxxxx/
>
> > Additional information: The decoded stack trace suggests that the
> > "id" parameter of pl011_probe() may be NULL.
>
> That's strange! I'll take a closer look once you confirm that the
> series above doesn't help.

That series does not make a difference.

Guenter