Re: [PATCH v3 2/4] irqchip/qcom-pdc: Switch to using IRQCHIP_PLATFORM_DRIVER helper macros

From: Steev Klimaszewski
Date: Wed Aug 05 2020 - 17:16:45 EST

On 8/5/20 3:19 PM, Saravana Kannan wrote:
> On Wed, Aug 5, 2020 at 12:44 AM John Stultz <john.stultz@xxxxxxxxxx> wrote:
>> <sigh>
>> So this is where I bashfully admit I didn't get a chance to try this
>> patch series out, as I had success with a much older version of
>> Saravana's macro magic.
>> But unfortunately, now that this has landed in mainline, I'm seeing
>> boot regressions on db845c. :( This is in the non-modular case,
>> building the driver in.
> Does that mean the modular version is working? Or you haven't tried
> that yet? I'll wait for your reply before I try to fix it. I don't
> have the hardware, but it should be easy to guess this issue looking
> at the code delta.

For what it's worth, I saw this too on the Lenovo C630 (started on -next
around 20200727, but I didn't track it down as, well, there's less way
to get debug output on the C630.

In my testing, module or built-in doesn't matter, but reverting does
allow me to boot again.

> The only significant change from what your probe function is doing is
> this snippet. But it'd be surprising if this only affects the builtin
> case.
> + if (par_np == np)
> + par_np = NULL;
> +
> + /*
> + * If there's a parent interrupt controller and none of the parent irq
> + * domains have been registered, that means the parent interrupt
> + * controller has not been initialized yet. it's not time for this
> + * interrupt controller to initialize. So, defer probe of this
> + * interrupt controller. The actual initialization callback of this
> + * interrupt controller can check for specific domains as necessary.
> + */
> + if (par_np && !irq_find_matching_host(np, DOMAIN_BUS_ANY))
> + return -EPROBE_DEFER;
>> I managed to bisect it down to this patch, and reverting it avoids the
>> issue. I don't see what is wrong right off, but I really need to get
>> to bed, so I'll dig further tomorrow.
>> Saravana: Apologies for not getting around to testing this beforehand!
> No worries. Apologies for breaking it accidentally.
> -Saravana