This change will send a CHANGE event to udev with the DEAD environment
variable set when the HC dies. I chose this instead of any of the other
udev events because it's representing a state change in the host
controller. The only other event that might have fit was OFFLINE, but
that seems to be used for hot-removal.
By notifying user space the appropriate policies can be applied.
e.g.,
* Collect error logs.
* Notify the user that USB is no longer functional.
* Perform a graceful reboot.
Signed-off-by: Raul E Rangel <rrangel@xxxxxxxxxxxx>
---
drivers/usb/core/hcd.c | 25 +++++++++++++++++++++++++
include/linux/usb/hcd.h | 1 +
2 files changed, 26 insertions(+)
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 975d7c1288e3..b38ad9ce068b 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -2343,6 +2343,22 @@ int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
return status;
}
+
+/**
+ * hcd_died_work - Workqueue routine for root-hub has died.
+ * @hcd: primary host controller for this root hub.
+ *
+ * Do not call with the shared_hcd.
+ * */
+static void hcd_died_work(struct work_struct *work)
+{
+ struct usb_hcd *hcd = container_of(work, struct usb_hcd, died_work);
+
+ /* Notify user space that the host controller has died */
+ kobject_uevent_env(&hcd->self.root_hub->dev.kobj, KOBJ_CHANGE,
+ (char *[]){ "DEAD=1", NULL });
+}
+
/* Workqueue routine for root-hub remote wakeup */
static void hcd_resume_work(struct work_struct *work)
{
@@ -2488,6 +2504,13 @@ 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. */
}
@@ -2555,6 +2578,8 @@ 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 :
diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index 695931b03684..ae51d5bd1dfc 100644
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -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 dying */
/*
* hardware info/state
--
2.21.0.392.gf8f6787159e-goog
