Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752794AbaBXQTk (ORCPT ); Mon, 24 Feb 2014 11:19:40 -0500 Received: from mga11.intel.com ([192.55.52.93]:63776 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751722AbaBXQTj (ORCPT ); Mon, 24 Feb 2014 11:19:39 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,535,1389772800"; d="scan'208";a="487176381" From: Mathias Nyman To: Cc: , david.a.cohen@linux.intel.com, jianqiang.tang@intel.com, , , , Mathias Nyman Subject: [RFC PATCH v2] xhci: Prevent runtime pm from autosuspending during initialization Date: Mon, 24 Feb 2014 18:29:03 +0200 Message-Id: <1393259343-825-1-git-send-email-mathias.nyman@linux.intel.com> X-Mailer: git-send-email 1.8.1.2 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org xHCI driver has its own pci probe function that will call usb_hcd_pci_probe to register its usb-2 bus, and then continue to manually register the usb-3 bus. usb_hcd_pci_probe does a pm_runtime_put_noidle at the end and might thus trigger a runtime suspend before the usb-3 bus is ready. Prevent the runtime suspend by increasing the usage count in the beginning of xhci_pci_probe, and decrease it once the usb-3 bus is ready. xhci-platform driver is not using usb_hcd_pci_probe to set up busses and should not need to have it's usage count increased during probe. Signed-off-by: Mathias Nyman --- drivers/usb/host/xhci-pci.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c index 04f986d..ea7158b 100644 --- a/drivers/usb/host/xhci-pci.c +++ b/drivers/usb/host/xhci-pci.c @@ -190,6 +190,10 @@ static int xhci_pci_probe(struct pci_dev *dev, const struct pci_device_id *id) struct usb_hcd *hcd; driver = (struct hc_driver *)id->driver_data; + + /* Prevent USB-2 roothub runtime suspend until USB-3 is initialized. */ + pm_runtime_get_noresume(&dev->dev); + /* Register the USB 2.0 roothub. * FIXME: USB core must know to register the USB 2.0 roothub first. * This is sort of silly, because we could just set the HCD driver flags @@ -199,7 +203,7 @@ static int xhci_pci_probe(struct pci_dev *dev, const struct pci_device_id *id) retval = usb_hcd_pci_probe(dev, id); if (retval) - return retval; + goto put_runtime_pm; /* USB 2.0 roothub is stored in the PCI device now. */ hcd = dev_get_drvdata(&dev->dev); @@ -228,12 +232,17 @@ static int xhci_pci_probe(struct pci_dev *dev, const struct pci_device_id *id) if (xhci->quirks & XHCI_LPM_SUPPORT) hcd_to_bus(xhci->shared_hcd)->root_hub->lpm_capable = 1; + /* USB-2 and USB-3 roothubs initialized, allow runtime pm suspend */ + pm_runtime_put_noidle(&dev->dev); + return 0; put_usb3_hcd: usb_put_hcd(xhci->shared_hcd); dealloc_usb2_hcd: usb_hcd_pci_remove(dev); +put_runtime_pm: + pm_runtime_put_noidle(&dev->dev); return retval; } -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/