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

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

[Alex Williamson]

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; "

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

[Gavin Shan]

On Thu, Jun 12, 2014 at 09:28:07AM -0600, Alex Williamson wrote:
>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

Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com>

>---
> 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; "
>

Thanks,
Gavin

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

[Bjorn Helgaas]

On Thu, Jun 12, 2014 at 09:28:07AM -0600, Alex Williamson wrote:
> 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

Applied with Gavin's ack to for-linus for v3.16, thanks!

> ---
>  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; "
>