From eb6e29248714d767d5338b8b82d286293e8a041a Mon Sep 17 00:00:00 2001 From: Petr Mladek Date: Fri, 19 Sep 2014 17:32:20 +0200 Subject: [PATCH] usb: hub: rename hub_events() to hub_event() and handle only one event there We would like to convert khubd kthread to a workqueue. As a result hub_events() will handle only one event per call. In fact, we could do this already now because there is another cycle in hub_thread(). It calls hub_events() until hub_event_list is empty. This patch renames the function to hub_event(), removes the while cycle, and renames the goto targets from loop* to out*. When touching the code, it fixes also formatting of dev_err() and dev_dbg() calls to make checkpatch.pl happy :-) Signed-off-by: Petr Mladek Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hub.c | 236 +++++++++++++++++++---------------------- 1 file changed, 111 insertions(+), 125 deletions(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 6a9f11fbc2e..b75749c3029 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -4996,8 +4996,7 @@ static void port_event(struct usb_hub *hub, int port1) hub_port_connect_change(hub, port1, portstatus, portchange); } - -static void hub_events(void) +static void hub_event(void) { struct list_head *tmp; struct usb_device *hdev; @@ -5008,144 +5007,131 @@ static void hub_events(void) u16 hubchange; int i, ret; - /* - * We restart the list every time to avoid a deadlock with - * deleting hubs downstream from this one. This should be - * safe since we delete the hub from the event list. - * Not the most efficient, but avoids deadlocks. - */ - while (1) { + /* Grab the first entry at the beginning of the list */ + spin_lock_irq(&hub_event_lock); + if (list_empty(&hub_event_list)) { + spin_unlock_irq(&hub_event_lock); + return; + } - /* Grab the first entry at the beginning of the list */ - spin_lock_irq(&hub_event_lock); - if (list_empty(&hub_event_list)) { - spin_unlock_irq(&hub_event_lock); - break; - } + tmp = hub_event_list.next; + list_del_init(tmp); - tmp = hub_event_list.next; - list_del_init(tmp); + hub = list_entry(tmp, struct usb_hub, event_list); + kref_get(&hub->kref); + spin_unlock_irq(&hub_event_lock); - hub = list_entry(tmp, struct usb_hub, event_list); - kref_get(&hub->kref); - 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", + hdev->state, hdev->maxchild, + /* NOTE: expects max 15 ports... */ + (u16) hub->change_bits[0], + (u16) hub->event_bits[0]); + + /* Lock the device, then check to see if we were + * disconnected while waiting for the lock to succeed. */ + usb_lock_device(hdev); + if (unlikely(hub->disconnected)) + goto out_disconnected; + + /* If the hub has died, clean up after it */ + if (hdev->state == USB_STATE_NOTATTACHED) { + hub->error = -ENODEV; + hub_quiesce(hub, HUB_DISCONNECT); + goto out; + } + + /* Autoresume */ + ret = usb_autopm_get_interface(intf); + if (ret) { + dev_dbg(hub_dev, "Can't autoresume: %d\n", ret); + goto out; + } - 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", - hdev->state, hdev->maxchild, - /* NOTE: expects max 15 ports... */ - (u16) hub->change_bits[0], - (u16) hub->event_bits[0]); - - /* Lock the device, then check to see if we were - * disconnected while waiting for the lock to succeed. */ - usb_lock_device(hdev); - if (unlikely(hub->disconnected)) - goto loop_disconnected; - - /* If the hub has died, clean up after it */ - if (hdev->state == USB_STATE_NOTATTACHED) { - hub->error = -ENODEV; - hub_quiesce(hub, HUB_DISCONNECT); - goto loop; - } + /* If this is an inactive hub, do nothing */ + if (hub->quiescing) + goto out_autopm; + + if (hub->error) { + dev_dbg(hub_dev, "resetting for error %d\n", hub->error); - /* Autoresume */ - ret = usb_autopm_get_interface(intf); + ret = usb_reset_device(hdev); if (ret) { - dev_dbg(hub_dev, "Can't autoresume: %d\n", ret); - goto loop; + dev_dbg(hub_dev, "error resetting hub: %d\n", ret); + goto out_autopm; } - /* If this is an inactive hub, do nothing */ - if (hub->quiescing) - goto loop_autopm; + hub->nerrors = 0; + hub->error = 0; + } - if (hub->error) { - dev_dbg (hub_dev, "resetting for error %d\n", - hub->error); + /* deal with port status changes */ + for (i = 1; i <= hdev->maxchild; i++) { + struct usb_port *port_dev = hub->ports[i - 1]; - ret = usb_reset_device(hdev); - if (ret) { - dev_dbg (hub_dev, - "error resetting hub: %d\n", ret); - goto loop_autopm; - } - - hub->nerrors = 0; - hub->error = 0; + if (test_bit(i, hub->event_bits) + || test_bit(i, hub->change_bits) + || test_bit(i, hub->wakeup_bits)) { + /* + * The get_noresume and barrier ensure that if + * the port was in the process of resuming, we + * flush that work and keep the port active for + * the duration of the port_event(). However, + * if the port is runtime pm suspended + * (powered-off), we leave it in that state, run + * an abbreviated port_event(), and move on. + */ + pm_runtime_get_noresume(&port_dev->dev); + pm_runtime_barrier(&port_dev->dev); + usb_lock_port(port_dev); + port_event(hub, i); + usb_unlock_port(port_dev); + pm_runtime_put_sync(&port_dev->dev); } + } - /* deal with port status changes */ - for (i = 1; i <= hdev->maxchild; i++) { - struct usb_port *port_dev = hub->ports[i - 1]; - - if (test_bit(i, hub->event_bits) - || test_bit(i, hub->change_bits) - || test_bit(i, hub->wakeup_bits)) { - /* - * The get_noresume and barrier ensure that if - * the port was in the process of resuming, we - * flush that work and keep the port active for - * the duration of the port_event(). However, - * if the port is runtime pm suspended - * (powered-off), we leave it in that state, run - * an abbreviated port_event(), and move on. - */ - pm_runtime_get_noresume(&port_dev->dev); - pm_runtime_barrier(&port_dev->dev); - usb_lock_port(port_dev); - port_event(hub, i); - usb_unlock_port(port_dev); - pm_runtime_put_sync(&port_dev->dev); - } + /* deal with hub status changes */ + if (test_and_clear_bit(0, hub->event_bits) == 0) + ; /* do nothing */ + else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0) + dev_err(hub_dev, "get_hub_status failed\n"); + else { + if (hubchange & HUB_CHANGE_LOCAL_POWER) { + dev_dbg(hub_dev, "power change\n"); + clear_hub_feature(hdev, C_HUB_LOCAL_POWER); + if (hubstatus & HUB_STATUS_LOCAL_POWER) + /* FIXME: Is this always true? */ + hub->limited_power = 1; + else + hub->limited_power = 0; } + if (hubchange & HUB_CHANGE_OVERCURRENT) { + u16 status = 0; + u16 unused; - /* deal with hub status changes */ - if (test_and_clear_bit(0, hub->event_bits) == 0) - ; /* do nothing */ - else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0) - dev_err (hub_dev, "get_hub_status failed\n"); - else { - if (hubchange & HUB_CHANGE_LOCAL_POWER) { - dev_dbg (hub_dev, "power change\n"); - clear_hub_feature(hdev, C_HUB_LOCAL_POWER); - if (hubstatus & HUB_STATUS_LOCAL_POWER) - /* FIXME: Is this always true? */ - hub->limited_power = 1; - else - hub->limited_power = 0; - } - if (hubchange & HUB_CHANGE_OVERCURRENT) { - u16 status = 0; - u16 unused; - - dev_dbg(hub_dev, "over-current change\n"); - clear_hub_feature(hdev, C_HUB_OVER_CURRENT); - msleep(500); /* Cool down */ - hub_power_on(hub, true); - hub_hub_status(hub, &status, &unused); - if (status & HUB_STATUS_OVERCURRENT) - dev_err(hub_dev, "over-current " - "condition\n"); - } + dev_dbg(hub_dev, "over-current change\n"); + clear_hub_feature(hdev, C_HUB_OVER_CURRENT); + msleep(500); /* Cool down */ + hub_power_on(hub, true); + hub_hub_status(hub, &status, &unused); + if (status & HUB_STATUS_OVERCURRENT) + dev_err(hub_dev, "over-current condition\n"); } + } - loop_autopm: - /* Balance the usb_autopm_get_interface() above */ - usb_autopm_put_interface_no_suspend(intf); - loop: - /* Balance the usb_autopm_get_interface_no_resume() in - * kick_khubd() and allow autosuspend. - */ - usb_autopm_put_interface(intf); - loop_disconnected: - usb_unlock_device(hdev); - kref_put(&hub->kref, hub_release); - - } /* end while (1) */ +out_autopm: + /* Balance the usb_autopm_get_interface() above */ + usb_autopm_put_interface_no_suspend(intf); +out: + /* Balance the usb_autopm_get_interface_no_resume() in + * kick_khubd() and allow autosuspend. + */ + usb_autopm_put_interface(intf); +out_disconnected: + usb_unlock_device(hdev); + kref_put(&hub->kref, hub_release); } static int hub_thread(void *__unused) @@ -5158,7 +5144,7 @@ static int hub_thread(void *__unused) set_freezable(); do { - hub_events(); + hub_event(); wait_event_freezable(khubd_wait, !list_empty(&hub_event_list) || kthread_should_stop()); -- 2.41.0