Re: [PATCH v2 1/1] mfd: intel-lpss: Fix too early PM enablement in the ACPI ->probe()

From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Aditya Garg <gargaditya08@live.com>
Cc: Lee Jones <lee.jones@linaro.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Orlando Chamberlain <redecorating@protonmail.com>
Subject: Re: [PATCH v2 1/1] mfd: intel-lpss: Fix too early PM enablement in the ACPI ->probe()
Date: Mon, 15 Nov 2021 12:36:06 +0200	[thread overview]
Message-ID: <YZI4FnCvAws2FLDA@smile.fi.intel.com> (raw)
In-Reply-To: <54F23B0A-9DB9-439A-B3BA-E1141703E91D@live.com>

On Tue, Nov 02, 2021 at 05:42:35AM +0000, Aditya Garg wrote:
> > On 02-Nov-2021, at 12:30 AM, Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:

> > The runtime PM callback may be called as soon as the runtime PM facility
> > is enabled and activated. It means that ->suspend() may be called before
> > we finish probing the device in the ACPI case. Hence, NULL pointer
> > dereference:
> > 
> >  intel-lpss INT34BA:00: IRQ index 0 not found
> >  BUG: kernel NULL pointer dereference, address: 0000000000000030
> >  ...
> >  Workqueue: pm pm_runtime_work
> >  RIP: 0010:intel_lpss_suspend+0xb/0x40 [intel_lpss]
> > 
> > To fix this, first try to register the device and only after that enable
> > runtime PM facility.
> > 
> > Fixes: 4b45efe85263 ("mfd: Add support for Intel Sunrisepoint LPSS devices")
> > Reported-by: Orlando Chamberlain <redecorating@protonmail.com>
> > Reported-by: Aditya Garg <gargaditya08@live.com>
> > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > Tested-by: Aditya Garg <gargaditya08@live.com>
> > ---
> > v2: added tag (Aditya), returned 0 explicitly at the end of ->probe()

> It works

Thanks for testing again!

Lee, can we have this as a fix material for v5.16-rcX?

-- 
With Best Regards,
Andy Shevchenko