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From:   Jason Liu <jason.hui.liu@nxp.com>
To:     Sudeep Holla <sudeep.holla@arm.com>
CC:     Marc Zyngier <maz@kernel.org>,
        "catalin.marinas@arm.com" <catalin.marinas@arm.com>,
        "will@kernel.org" <will@kernel.org>,
        "sashal@kernel.org" <sashal@kernel.org>,
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        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>
Subject: RE: [PATCH 1/1] arm64: kexec: no need to do irq_chip->irq_mask if it
 already masked
Thread-Topic: [PATCH 1/1] arm64: kexec: no need to do irq_chip->irq_mask if it
 already masked
Thread-Index: AQHWaj3ZMAA/XWH8SkmG3qCWNnZEoaknx/iAgAALMQCAAQxYoIAAVj6AgAGoCSA=
Date:   Thu, 6 Aug 2020 10:09:36 +0000
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> -----Original Message-----
> From: Sudeep Holla <sudeep.holla@arm.com>
> Sent: Wednesday, August 5, 2020 4:48 PM
> To: Jason Liu <jason.hui.liu@nxp.com>
> Cc: Marc Zyngier <maz@kernel.org>; catalin.marinas@arm.com;
> will@kernel.org; sashal@kernel.org; linux-kernel@vger.kernel.org; Sudeep
> Holla <sudeep.holla@arm.com>; linux-arm-kernel@lists.infradead.org
> Subject: Re: [PATCH 1/1] arm64: kexec: no need to do irq_chip->irq_mask i=
f it
> already masked
>=20
> On Wed, Aug 05, 2020 at 06:31:20AM +0000, Jason Liu wrote:
> > >
> > > Indeed, the runtime PM ops in that driver looks dodgy. Any calls to
> > > mask_irq from drivers or anywhere with irqchip suspended with just
> > > blows up the system.
> >
> > If you look at the chip->irq_mask implementation on different
> > platforms, almost all with directly access the register of the irqchip =
including
> irqsteer.
> > There are fine due to driver will use the common mask_irq API.
> >
>=20
> That still doesn't explain how you can prevent system from blowing up if
> chip->irq_mask gets called with irqchip suspended ?

Do you mean driver, the driver will not call chip->irq_mask when irqchip wa=
s in suspend.
if it does, it will be big BUG. I believe we don't do that in the driver.

>=20
> --
> Regards,
> Sudeep