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Commit a4d6a298 authored by Raul E Rangel's avatar Raul E Rangel Committed by Greg Kroah-Hartman
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usb/hcd: Send a uevent signaling that the host controller had died 



This change will send an OFFLINE event to udev with the ERROR=DEAD
environment variable set when the HC dies.

By notifying user space the appropriate policies can be applied.
i.e.,
 * Collect error logs.
 * Notify the user that USB is no longer functional.
 * Perform a graceful reboot.

Reported-by: default avatarkbuild test robot <lkp@intel.com>
Signed-off-by: default avatarRaul E Rangel <rrangel@chromium.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent cf28369c

Documentation/ABI/testing/usb-uevent

0 → 100644
+27 −0
Original line number Diff line number Diff line 
What:		Raise a uevent when a USB Host Controller has died

Date:		2019-04-17

KernelVersion:	5.2

Contact:	linux-usb@vger.kernel.org

Description:	When the USB Host Controller has entered a state where it is no

		longer functional a uevent will be raised. The uevent will

		contain ACTION=offline and ERROR=DEAD.



		Here is an example taken using udevadm monitor -p:



		KERNEL[130.428945] offline  /devices/pci0000:00/0000:00:10.0/usb2 (usb)

		ACTION=offline

		BUSNUM=002

		DEVNAME=/dev/bus/usb/002/001

		DEVNUM=001

		DEVPATH=/devices/pci0000:00/0000:00:10.0/usb2

		DEVTYPE=usb_device

		DRIVER=usb

		ERROR=DEAD

		MAJOR=189

		MINOR=128

		PRODUCT=1d6b/2/414

		SEQNUM=2168

		SUBSYSTEM=usb

		TYPE=9/0/1



Users:		chromium-os-dev@chromium.org

drivers/usb/core/hcd.c

+24 −0
Original line number Diff line number Diff line
@@ -2435,6 +2435,19 @@ EXPORT_SYMBOL_GPL(usb_hcd_irq); 


/*-------------------------------------------------------------------------*/



/* Workqueue routine for when the root-hub has died. */

static void hcd_died_work(struct work_struct *work)

{

	struct usb_hcd *hcd = container_of(work, struct usb_hcd, died_work);

	static char *env[] = {

		"ERROR=DEAD",

		NULL

	};



	/* Notify user space that the host controller has died */

	kobject_uevent_env(&hcd->self.root_hub->dev.kobj, KOBJ_OFFLINE, env);

}



/**

 * usb_hc_died - report abnormal shutdown of a host controller (bus glue)

 * @hcd: pointer to the HCD representing the controller
@@ -2475,6 +2488,13 @@ void usb_hc_died (struct usb_hcd *hcd) 
			usb_kick_hub_wq(hcd->self.root_hub);

		}

	}



	/* Handle the case where this function gets called with a shared HCD */

	if (usb_hcd_is_primary_hcd(hcd))

		schedule_work(&hcd->died_work);

	else

		schedule_work(&hcd->primary_hcd->died_work);



	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);

	/* Make sure that the other roothub is also deallocated. */

}
@@ -2542,6 +2562,8 @@ struct usb_hcd *__usb_create_hcd(const struct hc_driver *driver, 
	INIT_WORK(&hcd->wakeup_work, hcd_resume_work);

#endif



	INIT_WORK(&hcd->died_work, hcd_died_work);



	hcd->driver = driver;

	hcd->speed = driver->flags & HCD_MASK;

	hcd->product_desc = (driver->product_desc) ? driver->product_desc :
@@ -2895,6 +2917,7 @@ int usb_add_hcd(struct usb_hcd *hcd, 
#ifdef CONFIG_PM

	cancel_work_sync(&hcd->wakeup_work);

#endif

	cancel_work_sync(&hcd->died_work);

	mutex_lock(&usb_bus_idr_lock);

	usb_disconnect(&rhdev);		/* Sets rhdev to NULL */

	mutex_unlock(&usb_bus_idr_lock);
@@ -2955,6 +2978,7 @@ void usb_remove_hcd(struct usb_hcd *hcd) 
#ifdef CONFIG_PM

	cancel_work_sync(&hcd->wakeup_work);

#endif

	cancel_work_sync(&hcd->died_work);



	mutex_lock(&usb_bus_idr_lock);

	usb_disconnect(&rhdev);		/* Sets rhdev to NULL */

include/linux/usb/hcd.h

+1 −0
Original line number Diff line number Diff line
@@ -98,6 +98,7 @@ struct usb_hcd { 
#ifdef CONFIG_PM

	struct work_struct	wakeup_work;	/* for remote wakeup */

#endif

	struct work_struct	died_work;	/* for when the device dies */



	/*

	 * hardware info/state