On Tue, Nov 29, 2016 at 12:00:40PM -0600, Matthew R. Ochs wrote:
> The PCI core uses a fixed 50ms timeout when waiting for VPD accesses to
> complete. When an access does not complete within this period, a warning
> is logged and an error returned to the caller.
>
> While this default timeout is valid for most hardware, some devices can
> experience longer access delays under certain circumstances. For example,
> one of the IBM CXL Flash devices can take up to ~120ms in a worst-case
> scenario. These types of devices can benefit from an extended timeout.
>
> To support devices with a longer access delay, increase the timeout in
> pci_vpd_wait() to 125ms. The PCI specification is silent with respect to
> VPD delays, therefore there is no concern for violating a threshold.
>
> Signed-off-by: Matthew R. Ochs <mrochs@xxxxxxxxxxxxxxxxxx>
Applied to pci/vpd for v4.11, with Tested-by Uma and Reviewed-by Gavin,
thanks!
> ---
> drivers/pci/access.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pci/access.c b/drivers/pci/access.c
> index d11cdbb..61b5a6b 100644
> --- a/drivers/pci/access.c
> +++ b/drivers/pci/access.c
> @@ -355,7 +355,7 @@ static size_t pci_vpd_size(struct pci_dev *dev, size_t old_size)
> static int pci_vpd_wait(struct pci_dev *dev)
> {
> struct pci_vpd *vpd = dev->vpd;
> - unsigned long timeout = jiffies + msecs_to_jiffies(50);
> + unsigned long timeout = jiffies + msecs_to_jiffies(125);
> unsigned long max_sleep = 16;
> u16 status;
> int ret;
> --
> 2.1.0
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
