Re: [PATCH 2/7] PCI: aardvark: Check for virq mapping when processing INTx IRQ

From: Marc Zyngier <maz@kernel.org>
To: "Pali Rohár" <pali@kernel.org>
Cc: "Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
	"Thomas Petazzoni" <thomas.petazzoni@bootlin.com>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	"Rob Herring" <robh@kernel.org>, "Marek Behún" <kabel@kernel.org>,
	linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/7] PCI: aardvark: Check for virq mapping when processing INTx IRQ
Date: Mon, 23 Aug 2021 17:47:24 +0100	[thread overview]
Message-ID: <8735r0qfab.wl-maz@kernel.org> (raw)
In-Reply-To: <20210823163305.okizte3ejnm6ltra@pali>

On Mon, 23 Aug 2021 17:33:05 +0100,
Pali Rohár <pali@kernel.org> wrote:
> 
> On Friday 06 August 2021 09:29:02 Marc Zyngier wrote:
> > On 2021-06-25 10:03, Pali Rohár wrote:
> > > It is possible that we receive spurious INTx interrupt. So add needed
> > > check
> > > before calling generic_handle_irq() function.
> > > 
> > > Signed-off-by: Pali Rohár <pali@kernel.org>
> > > Reviewed-by: Marek Behún <kabel@kernel.org>
> > > Cc: stable@vger.kernel.org
> > > ---
> > >  drivers/pci/controller/pci-aardvark.c | 6 +++++-
> > >  1 file changed, 5 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/pci/controller/pci-aardvark.c
> > > b/drivers/pci/controller/pci-aardvark.c
> > > index 36fcc077ec72..59f91fad2481 100644
> > > --- a/drivers/pci/controller/pci-aardvark.c
> > > +++ b/drivers/pci/controller/pci-aardvark.c
> > > @@ -1226,7 +1226,11 @@ static void advk_pcie_handle_int(struct advk_pcie
> > > *pcie)
> > >  			    PCIE_ISR1_REG);
> > > 
> > >  		virq = irq_find_mapping(pcie->irq_domain, i);
> > > -		generic_handle_irq(virq);
> > > +		if (virq)
> > > +			generic_handle_irq(virq);
> > > +		else
> > > +			dev_err_ratelimited(&pcie->pdev->dev, "unexpected INT%c IRQ\n",
> > > +					    (char)i+'A');
> > >  	}
> > >  }
> > 
> > Please use generic_handle_domain_irq() instead of irq_find_mapping()
> > and generic_handle_irq().
> 
> Ok! At the time when I was sending these patches there was no function
> generic_handle_domain_irq().
> 
> As all these interrupt related patches are targeting also stable tress
> where is no generic_handle_domain_irq() function too, it would be easier
> for backporting to use irq_find_mapping() + generic_handle_irq(). And
> later after applying all interrupt related patches, include a patch
> which converts all usage to generic_handle_domain_irq().

That's not how it works, and I have already done the work converting
all the existing users to the new API, already queued in -next.

Please send a patch that makes sense for upstream, and a different
patch that applies to previous version.

	M.

-- 
Without deviation from the norm, progress is not possible.