From 074f9dd55f9cab1b82690ed7e44bcf38b9616ce0 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Thu, 29 Jan 2015 15:05:04 -0500 Subject: USB: add flag for HCDs that can't receive wakeup requests (isp1760-hcd) Currently the USB stack assumes that all host controller drivers are capable of receiving wakeup requests from downstream devices. However, this isn't true for the isp1760-hcd driver, which means that it isn't safe to do a runtime suspend of any device attached to a root-hub port if the device requires wakeup. This patch adds a "cant_recv_wakeups" flag to the usb_hcd structure and sets the flag in isp1760-hcd. The core is modified to prevent a direct child of the root hub from being put into runtime suspend with wakeup enabled if the flag is set. Signed-off-by: Alan Stern Tested-by: Nicolas Pitre CC: Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/driver.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'drivers/usb/core') diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index c76ec9758ce3..818369afff63 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -1780,6 +1780,18 @@ static int autosuspend_check(struct usb_device *udev) dev_dbg(&udev->dev, "remote wakeup needed for autosuspend\n"); return -EOPNOTSUPP; } + + /* + * If the device is a direct child of the root hub and the HCD + * doesn't handle wakeup requests, don't allow autosuspend when + * wakeup is needed. + */ + if (w && udev->parent == udev->bus->root_hub && + bus_to_hcd(udev->bus)->cant_recv_wakeups) { + dev_dbg(&udev->dev, "HCD doesn't handle wakeup requests\n"); + return -EOPNOTSUPP; + } + udev->do_remote_wakeup = w; return 0; } -- cgit v1.2.3