From 7dd830b8315230e29f958fd0e039e9eecad28c5d Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Thu, 29 Nov 2012 15:05:57 +0100 Subject: [PATCH] USB: hub: handle claim of enabled remote wakeup after reset commit 07e72b95f5038cc82304b9a4a2eb7f9fc391ea68 upstream. Some touchscreens have buggy firmware which claims remote wakeup to be enabled after a reset. They nevertheless crash if the feature is cleared by the host. Add a check for reset resume before checking for an enabled remote wakeup feature. On compliant devices the feature must be cleared after a reset anyway. Signed-off-by: Oliver Neukum Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hub.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index dbc4bf753746..ef8f790d6172 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -2609,7 +2609,7 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg) static int finish_port_resume(struct usb_device *udev) { int status = 0; - u16 devstatus; + u16 devstatus = 0; /* caller owns the udev device lock */ dev_dbg(&udev->dev, "%s\n", @@ -2654,7 +2654,13 @@ static int finish_port_resume(struct usb_device *udev) if (status) { dev_dbg(&udev->dev, "gone after usb resume? status %d\n", status); - } else if (udev->actconfig) { + /* + * There are a few quirky devices which violate the standard + * by claiming to have remote wakeup enabled after a reset, + * which crash if the feature is cleared, hence check for + * udev->reset_resume + */ + } else if (udev->actconfig && !udev->reset_resume) { le16_to_cpus(&devstatus); if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP)) { status = usb_control_msg(udev, -- 2.39.5