From:   Thomas Gleixner <tglx@linutronix.de>
To:     Nathan Chancellor <nathan@kernel.org>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Bjorn Helgaas <helgaas@kernel.org>,
        Marc Zygnier <maz@kernel.org>,
        Alex Williamson <alex.williamson@redhat.com>,
        Kevin Tian <kevin.tian@intel.com>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Megha Dey <megha.dey@intel.com>,
        Ashok Raj <ashok.raj@intel.com>, linux-pci@vger.kernel.org,
        Cedric Le Goater <clg@kaod.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Juergen Gross <jgross@suse.com>,
        xen-devel@lists.xenproject.org, Arnd Bergmann <arnd@arndb.de>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        linuxppc-dev@lists.ozlabs.org, Bjorn Helgaas <bhelgaas@google.com>,
        Stuart Yoder <stuyoder@gmail.com>,
        Laurentiu Tudor <laurentiu.tudor@nxp.com>,
        Nishanth Menon <nm@ti.com>, Tero Kristo <kristo@kernel.org>,
        Santosh Shilimkar <ssantosh@kernel.org>,
        linux-arm-kernel@lists.infradead.org,
        Vinod Koul <vkoul@kernel.org>, dmaengine@vger.kernel.org,
        Mark Rutland <mark.rutland@arm.com>,
        Will Deacon <will@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        Joerg Roedel <joro@8bytes.org>,
        iommu@lists.linux-foundation.org,
        Jassi Brar <jassisinghbrar@gmail.com>,
        Peter Ujfalusi <peter.ujfalusi@gmail.com>,
        Sinan Kaya <okaya@kernel.org>
Subject: Re: [patch V3 28/35] PCI/MSI: Simplify pci_irq_get_affinity()
In-Reply-To: <Yb0PaCyo/6z3XOlf@archlinux-ax161>
References: <20211210221642.869015045@linutronix.de>
 <20211210221814.900929381@linutronix.de>
 <Yb0PaCyo/6z3XOlf@archlinux-ax161>
Date:   Sat, 18 Dec 2021 11:25:14 +0100
Message-ID: <87v8zm9pmd.ffs@tglx>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

On Fri, Dec 17 2021 at 15:30, Nathan Chancellor wrote:
> On Fri, Dec 10, 2021 at 11:19:26PM +0100, Thomas Gleixner wrote:
> I just bisected a boot failure on my AMD test desktop to this patch as
> commit f48235900182 ("PCI/MSI: Simplify pci_irq_get_affinity()") in
> -next. It looks like there is a problem with the NVMe drive after this
> change according to the logs. Given that the hard drive is not getting
> mounted for journald to write logs to, I am not really sure how to get
> them from the machine so I have at least taken a picture of what I see
> on my screen; open to ideas on that front!

Bah. Fix below.

Thanks,

        tglx
---
diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c
index 71802410e2ab..9b4910befeda 100644
--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -1100,7 +1100,7 @@ EXPORT_SYMBOL(pci_irq_vector);
  */
 const struct cpumask *pci_irq_get_affinity(struct pci_dev *dev, int nr)
 {
-	int irq = pci_irq_vector(dev, nr);
+	int idx, irq = pci_irq_vector(dev, nr);
 	struct msi_desc *desc;
 
 	if (WARN_ON_ONCE(irq <= 0))
@@ -1113,7 +1113,10 @@ const struct cpumask *pci_irq_get_affinity(struct pci_dev *dev, int nr)
 
 	if (WARN_ON_ONCE(!desc->affinity))
 		return NULL;
-	return &desc->affinity[nr].mask;
+
+	/* MSI has a mask array in the descriptor. */
+	idx = dev->msi_enabled ? nr : 0;
+	return &desc->affinity[idx].mask;
 }
 EXPORT_SYMBOL(pci_irq_get_affinity);