From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Stefan Roese <sr@denx.de>,
        Thomas Gleixner <tglx@linutronix.de>,
        linux-pci@vger.kernel.org, Bjorn Helgaas <bhelgaas@google.com>,
        Michal Simek <michal.simek@xilinx.com>,
        Marek Vasut <marex@denx.de>
Subject: [PATCH 4.19 32/56] PCI/MSI: Clear PCI_MSIX_FLAGS_MASKALL on error
Date:   Mon, 20 Dec 2021 15:34:25 +0100
Message-Id: <20211220143024.496764056@linuxfoundation.org>
In-Reply-To: <20211220143023.451982183@linuxfoundation.org>
References: <20211220143023.451982183@linuxfoundation.org>
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From: Thomas Gleixner <tglx@linutronix.de>

commit 94185adbfad56815c2c8401e16d81bdb74a79201 upstream.

PCI_MSIX_FLAGS_MASKALL is set in the MSI-X control register at MSI-X
interrupt setup time. It's cleared on success, but the error handling path
only clears the PCI_MSIX_FLAGS_ENABLE bit.

That's incorrect as the reset state of the PCI_MSIX_FLAGS_MASKALL bit is
zero. That can be observed via lspci:

        Capabilities: [b0] MSI-X: Enable- Count=67 Masked+

Clear the bit in the error path to restore the reset state.

Fixes: 438553958ba1 ("PCI/MSI: Enable and mask MSI-X early")
Reported-by: Stefan Roese <sr@denx.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Stefan Roese <sr@denx.de>
Cc: linux-pci@vger.kernel.org
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Marek Vasut <marex@denx.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87tufevoqx.ffs@tglx
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/pci/msi.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -850,7 +850,7 @@ out_free:
 	free_msi_irqs(dev);
 
 out_disable:
-	pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0);
+	pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL | PCI_MSIX_FLAGS_ENABLE, 0);
 
 	return ret;
 }