[PATCH 4.4 13/23] PCI/MSI: Clear PCI_MSIX_FLAGS_MASKALL on error

[Greg Kroah-Hartman]

From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

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@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Tested-by: Stefan Roese <sr@xxxxxxx>
Cc: linux-pci@xxxxxxxxxxxxxxx
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: Michal Simek <michal.simek@xxxxxxxxxx>
Cc: Marek Vasut <marex@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/87tufevoqx.ffs@tglx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/pci/msi.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -840,7 +840,7 @@ 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;
 }