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

[Bjorn Helgaas <bhelgaas@google.com>]

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; "
>