usb: make usb_port flags atomic, rename did_runtime_put to child_usage

We want to manipulate ->did_runtime_put in usb_port_runtime_resume(),
but we don't want that to collide with other updates.  Move usb_port
flags to new port-bitmap fields in usb_hub. "did_runtime_put" is renamed
"child_usage_bits" to reflect that it is strictly standing in for the
fact that usb_devices are not the device_model children of their parent
port.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 20 insertions, 19 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 5a909ba6fb67..31a492a4a881 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -751,16 +751,20 @@ int usb_hub_set_port_power(struct usb_device *hdev, struct usb_hub *hub,
                            int port1, bool set)
 {
         int ret;
-        struct usb_port *port_dev = hub->ports[port1 - 1];
 
         if (set)
                 ret = set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
         else
                 ret = usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
 
-        if (!ret)
-                port_dev->power_is_on = set;
-        return ret;
+        if (ret)
+                return ret;
+
+        if (set)
+                set_bit(port1, hub->power_bits);
+        else
+                clear_bit(port1, hub->power_bits);
+        return 0;
 }
 
 /**
@@ -839,7 +843,7 @@ static unsigned hub_power_on(struct usb_hub *hub, bool do_delay)
                 dev_dbg(hub->intfdev, "trying to enable port power on "
                                 "non-switchable hub\n");
         for (port1 = 1; port1 <= hub->hdev->maxchild; port1++)
-                if (hub->ports[port1 - 1]->power_is_on)
+                if (test_bit(port1, hub->power_bits))
                         set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);
                 else
                         usb_clear_port_feature(hub->hdev, port1,
@@ -1180,15 +1184,13 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
                                 set_bit(port1, hub->change_bits);
 
                 } else if (udev->persist_enabled) {
-                        struct usb_port *port_dev = hub->ports[port1 - 1];
-
 #ifdef CONFIG_PM
                         udev->reset_resume = 1;
 #endif
                         /* Don't set the change_bits when the device
                          * was powered off.
                          */
-                        if (port_dev->power_is_on)
+                        if (test_bit(port1, hub->power_bits))
                                 set_bit(port1, hub->change_bits);
 
                 } else {
@@ -2096,16 +2098,15 @@ void usb_disconnect(struct usb_device **pdev)
         usb_hcd_synchronize_unlinks(udev);
 
         if (udev->parent) {
+                int port1 = udev->portnum;
                 struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
-                struct usb_port *port_dev = hub->ports[udev->portnum - 1];
+                struct usb_port *port_dev = hub->ports[port1 - 1];
 
                 sysfs_remove_link(&udev->dev.kobj, "port");
                 sysfs_remove_link(&port_dev->dev.kobj, "device");
 
-                if (!port_dev->did_runtime_put)
+                if (test_and_clear_bit(port1, hub->child_usage_bits))
                         pm_runtime_put(&port_dev->dev);
-                else
-                        port_dev->did_runtime_put = false;
         }
 
         usb_remove_ep_devs(&udev->ep0);
@@ -2416,7 +2417,8 @@ int usb_new_device(struct usb_device *udev)
         /* Create link files between child device and usb port device. */
         if (udev->parent) {
                 struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
-                struct usb_port *port_dev = hub->ports[udev->portnum - 1];
+                int port1 = udev->portnum;
+                struct usb_port *port_dev = hub->ports[port1 - 1];
 
                 err = sysfs_create_link(&udev->dev.kobj,
                                 &port_dev->dev.kobj, "port");
@@ -2430,7 +2432,8 @@ int usb_new_device(struct usb_device *udev)
                         goto fail;
                 }
 
-                pm_runtime_get_sync(&port_dev->dev);
+                if (!test_and_set_bit(port1, hub->child_usage_bits))
+                        pm_runtime_get_sync(&port_dev->dev);
         }
 
         (void) usb_create_ep_devs(&udev->dev, &udev->ep0, udev);
@@ -3100,10 +3103,9 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
                 usb_set_device_state(udev, USB_STATE_SUSPENDED);
         }
 
-        if (status == 0 && !udev->do_remote_wakeup && udev->persist_enabled) {
+        if (status == 0 && !udev->do_remote_wakeup && udev->persist_enabled
+                        && test_and_clear_bit(port1, hub->child_usage_bits))
                 pm_runtime_put_sync(&port_dev->dev);
-                port_dev->did_runtime_put = true;
-        }
 
         usb_mark_last_busy(hub->hdev);
         return status;
@@ -3245,9 +3247,8 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg)
         int             status;
         u16             portchange, portstatus;
 
-        if (port_dev->did_runtime_put) {
+        if (!test_and_set_bit(port1, hub->child_usage_bits)) {
                 status = pm_runtime_get_sync(&port_dev->dev);
-                port_dev->did_runtime_put = false;
                 if (status < 0) {
                         dev_dbg(&udev->dev, "can't resume usb port, status %d\n",
                                         status);