When the topology of the nested hubs are over 6 layers
Send uevent to user space when USB TOPO layer over 6.
Let end user more understand what happened.
Signed-off-by: Ricky Niu <rickyniu@xxxxxxxxxx>
---
drivers/usb/core/hub.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 7f71218cc1e5..e5e924526822 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -55,6 +55,10 @@ static DEFINE_SPINLOCK(device_state_lock);
static struct workqueue_struct *hub_wq;
static void hub_event(struct work_struct *work);
+/* struct to notify userspace of hub events */
+static struct class *hub_class;
+static struct device *hub_device;
+
/* synchronize hub-port add/remove and peering operations */
DEFINE_MUTEX(usb_port_peer_mutex);
@@ -1764,6 +1768,13 @@ static bool hub_descriptor_is_sane(struct usb_host_interface *desc)
return true;
}
+static void hub_over_tier(void)
+{
+ char *envp[2] = { "HUB=OVERTIER", NULL };
+
+ kobject_uevent_env(&hub_device->kobj, KOBJ_CHANGE, envp);
+}
+
static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
{
struct usb_host_interface *desc;
@@ -1831,6 +1842,7 @@ static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
if (hdev->level == MAX_TOPO_LEVEL) {
dev_err(&intf->dev,
"Unsupported bus topology: hub nested too deep\n");
+ hub_over_tier();
return -E2BIG;
}
@@ -5680,6 +5692,13 @@ int usb_hub_init(void)
return -1;
}
+ hub_class = class_create(THIS_MODULE, "usb_hub");
+ if (IS_ERR(hub_class))
+ return PTR_ERR(hub_class);
+
+ hub_device =
+ device_create(hub_class, NULL, MKDEV(0, 0), NULL, "usb_hub");
+
/*
* The workqueue needs to be freezable to avoid interfering with
* USB-PERSIST port handover. Otherwise it might see that a full-speed
@@ -5699,6 +5718,9 @@ int usb_hub_init(void)
void usb_hub_cleanup(void)
{
+ if (!IS_ERR(hub_class))
+ class_destroy(hub_class);
+
destroy_workqueue(hub_wq);
/*
--
2.30.1.766.gb4fecdf3b7-goog
