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authorHuang Ying <ying.huang@intel.com>2012-12-26 10:39:23 -0700
committerBjorn Helgaas <bhelgaas@google.com>2012-12-26 10:39:23 -0700
commitc733b77475707cc3980542c86ee0ad5c841d544c (patch)
tree5a2fed17d994e0e88737283b3af5f0fa20375cb1
parent130f1b8f35f14d27c43da755f3c9226318c17f57 (diff)
PCI/PM: Do not suspend port if any subordinate device needs PME polling
Ulrich reported that his USB3 cardreader does not work reliably when connected to the USB3 port. It turns out that USB3 controller failed to awaken when plugging in the USB3 cardreader. Further experiments found that the USB3 host controller can only be awakened via polling, not via PME interrupt. But if the PCIe port to which the USB3 host controller is connected is suspended, we cannot poll the controller because its config space is not accessible when the PCIe port is in a low power state. To solve the issue, the PCIe port will not be suspended if any subordinate device needs PME polling. [bhelgaas: use bool consistently rather than mixing int/bool] Reference: http://lkml.kernel.org/r/50841CCC.9030809@uli-eckhardt.de Reported-by: Ulrich Eckhardt <usb@uli-eckhardt.de> Tested-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> CC: stable@vger.kernel.org # v3.6+
-rw-r--r--drivers/pci/pcie/portdrv_pci.c20
1 files changed, 19 insertions, 1 deletions
diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c
index d4824cb78b4..08c243ab034 100644
--- a/drivers/pci/pcie/portdrv_pci.c
+++ b/drivers/pci/pcie/portdrv_pci.c
@@ -134,10 +134,28 @@ static int pcie_port_runtime_resume(struct device *dev)
return 0;
}
+static int pci_dev_pme_poll(struct pci_dev *pdev, void *data)
+{
+ bool *pme_poll = data;
+
+ if (pdev->pme_poll)
+ *pme_poll = true;
+ return 0;
+}
+
static int pcie_port_runtime_idle(struct device *dev)
{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ bool 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