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Subject[PATCH v3 1/6] usb: hub: keep hub->dev reference all the time when struct usb_hub lives
Date
This is just a small optimization of the fix from the commit c605f3cdff53a743f6
("usb: hub: take hub->hdev reference when processing from eventlist).

We do not need to take the reference for each event. Instead we could get it
when struct usb_hub is allocated and put it when it is released. By other words,
we could handle it the same way as the reference for hub->intfdev.

The motivation is that it will make the life easier when switching from khubd
kthread to a workqueue.

Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Petr Mladek <pmladek@suse.cz>
---
drivers/usb/core/hub.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index d481c99a20d7..8f35e5158daf 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1634,6 +1634,7 @@ static void hub_release(struct kref *kref)
{
struct usb_hub *hub = container_of(kref, struct usb_hub, kref);

+ usb_put_dev(hub->hdev);
usb_put_intf(to_usb_interface(hub->intfdev));
kfree(hub);
}
@@ -1799,6 +1800,7 @@ descriptor_error:
INIT_DELAYED_WORK(&hub->leds, led_work);
INIT_DELAYED_WORK(&hub->init_work, NULL);
usb_get_intf(intf);
+ usb_get_dev(hdev);

usb_set_intfdata (intf, hub);
intf->needs_remote_wakeup = 1;
@@ -5024,10 +5026,9 @@ static void hub_events(void)

hub = list_entry(tmp, struct usb_hub, event_list);
kref_get(&hub->kref);
- hdev = hub->hdev;
- usb_get_dev(hdev);
spin_unlock_irq(&hub_event_lock);

+ hdev = hub->hdev;
hub_dev = hub->intfdev;
intf = to_usb_interface(hub_dev);
dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n",
@@ -5140,7 +5141,6 @@ static void hub_events(void)
usb_autopm_put_interface(intf);
loop_disconnected:
usb_unlock_device(hdev);
- usb_put_dev(hdev);
kref_put(&hub->kref, hub_release);

} /* end while (1) */
--
1.8.4


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