diff options
Diffstat (limited to 'drivers/usb/core/hcd.c')
-rw-r--r-- | drivers/usb/core/hcd.c | 43 |
1 files changed, 35 insertions, 8 deletions
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 174eb857a6b4..b81407518fdf 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -2458,11 +2458,13 @@ struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver, mutex_init(hcd->bandwidth_mutex); dev_set_drvdata(dev, hcd); } else { + mutex_lock(&usb_port_peer_mutex); hcd->bandwidth_mutex = primary_hcd->bandwidth_mutex; hcd->primary_hcd = primary_hcd; primary_hcd->primary_hcd = primary_hcd; hcd->shared_hcd = primary_hcd; primary_hcd->shared_hcd = hcd; + mutex_unlock(&usb_port_peer_mutex); } kref_init(&hcd->kref); @@ -2514,18 +2516,25 @@ EXPORT_SYMBOL_GPL(usb_create_hcd); * deallocated. * * Make sure to only deallocate the bandwidth_mutex when the primary HCD is - * freed. When hcd_release() is called for the non-primary HCD, set the - * primary_hcd's shared_hcd pointer to null (since the non-primary HCD will be - * freed shortly). + * freed. When hcd_release() is called for either hcd in a peer set + * invalidate the peer's ->shared_hcd and ->primary_hcd pointers to + * block new peering attempts */ -static void hcd_release (struct kref *kref) +static void hcd_release(struct kref *kref) { struct usb_hcd *hcd = container_of (kref, struct usb_hcd, kref); + mutex_lock(&usb_port_peer_mutex); if (usb_hcd_is_primary_hcd(hcd)) kfree(hcd->bandwidth_mutex); - else - hcd->shared_hcd->shared_hcd = NULL; + if (hcd->shared_hcd) { + struct usb_hcd *peer = hcd->shared_hcd; + + peer->shared_hcd = NULL; + if (peer->primary_hcd == hcd) + peer->primary_hcd = NULL; + } + mutex_unlock(&usb_port_peer_mutex); kfree(hcd); } @@ -2593,6 +2602,21 @@ static int usb_hcd_request_irqs(struct usb_hcd *hcd, return 0; } +/* + * Before we free this root hub, flush in-flight peering attempts + * and disable peer lookups + */ +static void usb_put_invalidate_rhdev(struct usb_hcd *hcd) +{ + struct usb_device *rhdev; + + mutex_lock(&usb_port_peer_mutex); + rhdev = hcd->self.root_hub; + hcd->self.root_hub = NULL; + mutex_unlock(&usb_port_peer_mutex); + usb_put_dev(rhdev); +} + /** * usb_add_hcd - finish generic HCD structure initialization and register * @hcd: the usb_hcd structure to initialize @@ -2653,7 +2677,9 @@ int usb_add_hcd(struct usb_hcd *hcd, retval = -ENOMEM; goto err_allocate_root_hub; } + mutex_lock(&usb_port_peer_mutex); hcd->self.root_hub = rhdev; + mutex_unlock(&usb_port_peer_mutex); switch (hcd->speed) { case HCD_USB11: @@ -2762,7 +2788,7 @@ err_hcd_driver_start: err_request_irq: err_hcd_driver_setup: err_set_rh_speed: - usb_put_dev(hcd->self.root_hub); + usb_put_invalidate_rhdev(hcd); err_allocate_root_hub: usb_deregister_bus(&hcd->self); err_register_bus: @@ -2842,7 +2868,6 @@ void usb_remove_hcd(struct usb_hcd *hcd) free_irq(hcd->irq, hcd); } - usb_put_dev(hcd->self.root_hub); usb_deregister_bus(&hcd->self); hcd_buffer_destroy(hcd); if (hcd->remove_phy && hcd->phy) { @@ -2850,6 +2875,8 @@ void usb_remove_hcd(struct usb_hcd *hcd) usb_put_phy(hcd->phy); hcd->phy = NULL; } + + usb_put_invalidate_rhdev(hcd); } EXPORT_SYMBOL_GPL(usb_remove_hcd); |