On Friday, December 14, 2012 10:52:11 AM Huang Ying wrote:
> In
>
> http://www.mail-archive.com/linux-usb@vger.kernel.org/msg07976.html
>
> Ulrich reported that his USB3 cardreader does not work reliably when
> connected to the USB3 port. It turns out that USB3 controller failed
> to be waken up when plugging in the USB3 cardreader. Further
> experiment found that the USB3 host controller can only be waken up
> via polling, while not via PME interrupt. But if the PCIe port that
> the USB3 host controller is connected is suspended, we can not poll
> the USB3 host controller because its config space is not accessible if
> the PCIe port is put into low power state.
>
> To solve the issue, the PCIe port will not be suspended if any
> subordinate device need PME polling.
>
> Reported-by: Ulrich Eckhardt <u...@uli-eckhardt.de>
> Signed-off-by: Huang Ying <ying.hu...@intel.com>
> Tested-by: Sarah Sharp <sarah.a.sh...@linux.intel.com>
> Cc: sta...@vger.kernel.org # 3.6+
> ---
> drivers/pci/pcie/portdrv_pci.c | 18 +++++++++++++++++-
> 1 file changed, 17 insertions(+), 1 deletion(-)
>
> --- a/drivers/pci/pcie/portdrv_pci.c
> +++ b/drivers/pci/pcie/portdrv_pci.c
> @@ -134,10 +134,26 @@ static int pcie_port_runtime_resume(stru
> return 0;
> }
>
> +static int pci_dev_pme_poll(struct pci_dev *pdev, void *data)
> +{
> + int *pme_poll = data;
> + *pme_poll = *pme_poll || pdev->pme_poll;
I would write that as
*pme_poll ||= pdev->pme_poll;
It is not a big deal, though.
> + return 0;
> +}
> +
> static int pcie_port_runtime_idle(struct device *dev)
> {
> + struct pci_dev *pdev = to_pci_dev(dev);
> + int pme_poll = false;
> +
> + /*
> + * If any subordinate device needs pme poll, we should keep
> + * the port in D0, because we need port in D0 to poll it.
> + */
> + pci_walk_bus(pdev->subordinate, pci_dev_pme_poll, &pme_poll);
> /* Delay for a short while to prevent too frequent suspend/resume */
> - pm_schedule_suspend(dev, 10);
> + if (!pme_poll)
> + pm_schedule_suspend(dev, 10);
> return -EBUSY;
> }
> #else
Acked-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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