Re: [PATCH] PCIe/PM: Do not suspend port if any subordinate deviceneed PME polling

[Bjorn Helgaas]

On Sun, Dec 16, 2012 at 6:11 AM, Richard Yang
<weiyang@xxxxxxxxxxxxxxxxxx> wrote:
> On Sat, Dec 15, 2012 at 12:03:33AM +0100, Rafael J. Wysocki wrote:
>>On Friday, December 14, 2012 01:11:31 PM Richard Yang wrote:
>>> On Fri, Dec 14, 2012 at 10:52:11AM +0800, Huang Ying wrote:
>>> >In
>>> >
>>> >  http://www.mail-archive.com/linux-usb@xxxxxxxxxxxxxxx/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 <usb@xxxxxxxxxxxxxxx>
>>> >Signed-off-by: Huang Ying <ying.huang@xxxxxxxxx>
>>> >Tested-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>
>>> >Cc: stable@xxxxxxxxxxxxxxx  # 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;
>>> >+   return 0;
>>> >+}
>>> >+
>>> > static int pcie_port_runtime_idle(struct device *dev)
>>> > {
>>> >+   struct pci_dev *pdev = to_pci_dev(dev);
>>> >+   int pme_poll = false;
>>>
>>> You want to use int or bool?
>>>
>>> I think bool is better?
>>
>>Well, bool would be nicer, but it's not a big deal.
>>
>
> Yep, not a big deal.

I fixed up the int/bool confusion and added this to my pci/for-3.8
branch.  I'll push it soon after v3.8-rc1.  Thanks!

Bjorn
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