[PATCH] pci: Fix unaligned access testing AF transaction pending

From: Alex Williamson <alex.williamson@redhat.com>
To: linux-pci@vger.kernel.org
Cc: bhelgaas@google.com, ben@decadent.org.uk,
	gwshan@linux.vnet.ibm.com, linux-kernel@vger.kernel.org
Subject: [PATCH] pci: Fix unaligned access testing AF transaction pending
Date: Thu, 12 Jun 2014 09:28:07 -0600	[thread overview]
Message-ID: <20140612152732.4162.23298.stgit@bling.home> (raw)

pci_wait_for_pending() uses word access, so we shouldn't be passing
an offset that is only byte aligned.  Use the control register offset
instead, shifting the mask to match.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Cc: stable@vger.kernel.org
---
 drivers/pci/pci.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 759475e..81012ec 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3109,8 +3109,13 @@ static int pci_af_flr(struct pci_dev *dev, int probe)
 	if (probe)
 		return 0;
 
-	/* Wait for Transaction Pending bit clean */
-	if (pci_wait_for_pending(dev, pos + PCI_AF_STATUS, PCI_AF_STATUS_TP))
+	/*
+	 * Wait for Transaction Pending bit to clear.  A word-aligned test
+	 * is used, so we use the conrol offset rather than status and shift
+	 * the test bit to match.
+	 */
+	if (pci_wait_for_pending(dev, pos + PCI_AF_CTRL,
+				 PCI_AF_STATUS_TP << 8))
 		goto clear;
 
 	dev_err(&dev->dev, "transaction is not cleared; "

