Merge: usb: hub: fix detection of high tier US3 devices behind suspended hubs

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/7115

JIRA: https://issues.redhat.com/browse/RHEL-100939
Depends: !7128

This fixes a bug disturbing the detection of USB3 devices that are con-
nected behind external suspended hubs when plugged in due to aggressive
hub runtime pm suspend.

Signed-off-by: Desnes Nunes <desnesn@redhat.com>

Approved-by: Tony Camuso <tcamuso@redhat.com>
Approved-by: David Arcari <darcari@redhat.com>
Approved-by: Bastien Nocera <bnocera@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: Augusto Caringi <acaringi@redhat.com>

Author: caringi

drivers/usb/core/hub.c

@@ -68,6 +68,12 @@
  */
 #define USB_SHORT_SET_ADDRESS_REQ_TIMEOUT	500  /* ms */
 
+/*
+ * Give SS hubs 200ms time after wake to train downstream links before
+ * assuming no port activity and allowing hub to runtime suspend back.
+ */
+#define USB_SS_PORT_U0_WAKE_TIME	200  /* ms */
+
 /* Protect struct usb_device->state and ->children members
  * Note: Both are also protected by ->dev.sem, except that ->state can
  * change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */
@@ -1095,6 +1101,7 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 			goto init2;
 		goto init3;
 	}
+
 	hub_get(hub);
 
 	/* The superspeed hub except for root hub has to use Hub Depth
@@ -1343,6 +1350,17 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 		device_unlock(&hdev->dev);
 	}
 
+	if (type == HUB_RESUME && hub_is_superspeed(hub->hdev)) {
+		/* give usb3 downstream links training time after hub resume */
+		usb_autopm_get_interface_no_resume(
+			to_usb_interface(hub->intfdev));
+
+		queue_delayed_work(system_power_efficient_wq,
+				   &hub->post_resume_work,
+				   msecs_to_jiffies(USB_SS_PORT_U0_WAKE_TIME));
+		return;
+	}
+
 	hub_put(hub);
 }
 
@@ -1361,6 +1379,14 @@ static void hub_init_func3(struct work_struct *ws)
 	hub_activate(hub, HUB_INIT3);
 }
 
+static void hub_post_resume(struct work_struct *ws)
+{
+	struct usb_hub *hub = container_of(ws, struct usb_hub, post_resume_work.work);
+
+	usb_autopm_put_interface_async(to_usb_interface(hub->intfdev));
+	hub_put(hub);
+}
+
 enum hub_quiescing_type {
 	HUB_DISCONNECT, HUB_PRE_RESET, HUB_SUSPEND
 };
@@ -1386,6 +1412,7 @@ static void hub_quiesce(struct usb_hub *hub, enum hub_quiescing_type type)
 
 	/* Stop hub_wq and related activity */
 	timer_delete_sync(&hub->irq_urb_retry);
+	flush_delayed_work(&hub->post_resume_work);
 	usb_kill_urb(hub->urb);
 	if (hub->has_indicators)
 		cancel_delayed_work_sync(&hub->leds);
@@ -1944,6 +1971,7 @@ static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
 	hub->hdev = hdev;
 	INIT_DELAYED_WORK(&hub->leds, led_work);
 	INIT_DELAYED_WORK(&hub->init_work, NULL);
+	INIT_DELAYED_WORK(&hub->post_resume_work, hub_post_resume);
 	INIT_WORK(&hub->events, hub_event);
 	INIT_LIST_HEAD(&hub->onboard_devs);
 	spin_lock_init(&hub->irq_urb_lock);

drivers/usb/core/hub.h

@@ -70,6 +70,7 @@ struct usb_hub {
 	u8			indicator[USB_MAXCHILDREN];
 	struct delayed_work	leds;
 	struct delayed_work	init_work;
+	struct delayed_work	post_resume_work;
 	struct work_struct      events;
 	spinlock_t		irq_urb_lock;
 	struct timer_list	irq_urb_retry;