[PATCH 1/1] arm64: kexec: no need to do irq_chip->irq_mask if it already masked

Jason Liu jason.hui.liu at nxp.com
Thu Aug 6 06:09:36 EDT 2020



> -----Original Message-----
> From: Sudeep Holla <sudeep.holla at arm.com>
> Sent: Wednesday, August 5, 2020 4:48 PM
> To: Jason Liu <jason.hui.liu at nxp.com>
> Cc: Marc Zyngier <maz at kernel.org>; catalin.marinas at arm.com;
> will at kernel.org; sashal at kernel.org; linux-kernel at vger.kernel.org; Sudeep
> Holla <sudeep.holla at arm.com>; linux-arm-kernel at lists.infradead.org
> Subject: Re: [PATCH 1/1] arm64: kexec: no need to do irq_chip->irq_mask if it
> already masked
> 
> 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.
> >
> 
> 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 was in suspend.
if it does, it will be big BUG. I believe we don't do that in the driver.

> 
> --
> Regards,
> Sudeep



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