Date:   Mon, 29 Nov 2021 11:59:34 +0000
From:   Lee Jones <lee.jones@linaro.org>
To:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc:     linux-kernel@vger.kernel.org,
        Orlando Chamberlain <redecorating@protonmail.com>,
        Aditya Garg <gargaditya08@live.com>
Subject: Re: [PATCH v2 1/1] mfd: intel-lpss: Fix too early PM enablement in
 the ACPI ->probe()
Message-ID: <YaTApiRJPQSLItYI@google.com>
References: <20211101190008.86473-1-andriy.shevchenko@linux.intel.com>
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On Mon, 01 Nov 2021, Andy Shevchenko 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()
>  drivers/mfd/intel-lpss-acpi.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)

Applied, thanks.

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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