usb/hcd: Send a uevent signaling that the host controller had died (a4d6a298) · Commits · 戴 / test

Documentation/ABI/testing/usb-uevent

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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 @@ error_create_attr_group:
		#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

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