diff mbox series

[SRU,F,2/2] UBUNTU: SAUCE: Revert "Revert "usb: core: hcd: Add support for deferring roothub registration""

Message ID ff4f837508b80b31fb716b44f27adaa4810550b0.1649357153.git.luke.nowakowskikrijger@canonical.com
State New
Headers show
Series Fix USB devices not being detected at boot | expand

Commit Message

Luke Nowakowski-Krijger April 7, 2022, 8 p.m. UTC
BugLink: https://bugs.launchpad.net/bugs/1968210

This reverts commit 664c864fa18a64fa4adc12dec96f0cbb0680a239.

Reintroduce this commit as it fixes an issue with certain intel xHCI
controllers where device enumeration happens before xHC is running,
causing USB devices not to be detected at boot time.

This commit will be reintroduced upstream due to previous bugs
being fixed, but lets reintroduce it now to fix the problem users are
experiencing.

Signed-off-by: Luke Nowakowski-Krijger <luke.nowakowskikrijger@canonical.com>
---
 drivers/usb/core/hcd.c  | 29 +++++++++++++++++++++++------
 include/linux/usb/hcd.h |  2 ++
 2 files changed, 25 insertions(+), 6 deletions(-)
diff mbox series

Patch

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 3debbf0736bc..da6b1711c013 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -2677,6 +2677,7 @@  int usb_add_hcd(struct usb_hcd *hcd,
 {
 	int retval;
 	struct usb_device *rhdev;
+	struct usb_hcd *shared_hcd;
 
 	if (!hcd->skip_phy_initialization && usb_hcd_is_primary_hcd(hcd)) {
 		hcd->phy_roothub = usb_phy_roothub_alloc(hcd->self.sysdev);
@@ -2833,13 +2834,26 @@  int usb_add_hcd(struct usb_hcd *hcd,
 		goto err_hcd_driver_start;
 	}
 
+	/* starting here, usbcore will pay attention to the shared HCD roothub */
+	shared_hcd = hcd->shared_hcd;
+	if (!usb_hcd_is_primary_hcd(hcd) && shared_hcd && HCD_DEFER_RH_REGISTER(shared_hcd)) {
+		retval = register_root_hub(shared_hcd);
+		if (retval != 0)
+			goto err_register_root_hub;
+
+		if (shared_hcd->uses_new_polling && HCD_POLL_RH(shared_hcd))
+			usb_hcd_poll_rh_status(shared_hcd);
+	}
+
 	/* starting here, usbcore will pay attention to this root hub */
-	retval = register_root_hub(hcd);
-	if (retval != 0)
-		goto err_register_root_hub;
+	if (!HCD_DEFER_RH_REGISTER(hcd)) {
+		retval = register_root_hub(hcd);
+		if (retval != 0)
+			goto err_register_root_hub;
 
-	if (hcd->uses_new_polling && HCD_POLL_RH(hcd))
-		usb_hcd_poll_rh_status(hcd);
+		if (hcd->uses_new_polling && HCD_POLL_RH(hcd))
+			usb_hcd_poll_rh_status(hcd);
+	}
 
 	return retval;
 
@@ -2876,6 +2890,7 @@  EXPORT_SYMBOL_GPL(usb_add_hcd);
 void usb_remove_hcd(struct usb_hcd *hcd)
 {
 	struct usb_device *rhdev = hcd->self.root_hub;
+	bool rh_registered;
 
 	dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);
 
@@ -2886,6 +2901,7 @@  void usb_remove_hcd(struct usb_hcd *hcd)
 
 	dev_dbg(hcd->self.controller, "roothub graceful disconnect\n");
 	spin_lock_irq (&hcd_root_hub_lock);
+	rh_registered = hcd->rh_registered;
 	hcd->rh_registered = 0;
 	spin_unlock_irq (&hcd_root_hub_lock);
 
@@ -2895,7 +2911,8 @@  void usb_remove_hcd(struct usb_hcd *hcd)
 	cancel_work_sync(&hcd->died_work);
 
 	mutex_lock(&usb_bus_idr_lock);
-	usb_disconnect(&rhdev);		/* Sets rhdev to NULL */
+	if (rh_registered)
+		usb_disconnect(&rhdev);		/* Sets rhdev to NULL */
 	mutex_unlock(&usb_bus_idr_lock);
 
 	/*
diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index 712b2a603645..c0eb85b2981e 100644
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -124,6 +124,7 @@  struct usb_hcd {
 #define HCD_FLAG_RH_RUNNING		5	/* root hub is running? */
 #define HCD_FLAG_DEAD			6	/* controller has died? */
 #define HCD_FLAG_INTF_AUTHORIZED	7	/* authorize interfaces? */
+#define HCD_FLAG_DEFER_RH_REGISTER	8	/* Defer roothub registration */
 
 	/* The flags can be tested using these macros; they are likely to
 	 * be slightly faster than test_bit().
@@ -134,6 +135,7 @@  struct usb_hcd {
 #define HCD_WAKEUP_PENDING(hcd)	((hcd)->flags & (1U << HCD_FLAG_WAKEUP_PENDING))
 #define HCD_RH_RUNNING(hcd)	((hcd)->flags & (1U << HCD_FLAG_RH_RUNNING))
 #define HCD_DEAD(hcd)		((hcd)->flags & (1U << HCD_FLAG_DEAD))
+#define HCD_DEFER_RH_REGISTER(hcd) ((hcd)->flags & (1U << HCD_FLAG_DEFER_RH_REGISTER))
 
 	/*
 	 * Specifies if interfaces are authorized by default