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- /*
- * Copyright (C) 2003-2008 Takahiro Hirofuchi
- *
- * This is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
- * USA.
- */
- #include <linux/kthread.h>
- #include <linux/export.h>
- #include "usbip_common.h"
- static int event_handler(struct usbip_device *ud)
- {
- usbip_dbg_eh("enter\n");
- /*
- * Events are handled by only this thread.
- */
- while (usbip_event_happened(ud)) {
- usbip_dbg_eh("pending event %lx\n", ud->event);
- /*
- * NOTE: shutdown must come first.
- * Shutdown the device.
- */
- if (ud->event & USBIP_EH_SHUTDOWN) {
- ud->eh_ops.shutdown(ud);
- ud->event &= ~USBIP_EH_SHUTDOWN;
- }
- /* Reset the device. */
- if (ud->event & USBIP_EH_RESET) {
- ud->eh_ops.reset(ud);
- ud->event &= ~USBIP_EH_RESET;
- }
- /* Mark the device as unusable. */
- if (ud->event & USBIP_EH_UNUSABLE) {
- ud->eh_ops.unusable(ud);
- ud->event &= ~USBIP_EH_UNUSABLE;
- }
- /* Stop the error handler. */
- if (ud->event & USBIP_EH_BYE)
- return -1;
- }
- return 0;
- }
- static int event_handler_loop(void *data)
- {
- struct usbip_device *ud = data;
- while (!kthread_should_stop()) {
- wait_event_interruptible(ud->eh_waitq,
- usbip_event_happened(ud) ||
- kthread_should_stop());
- usbip_dbg_eh("wakeup\n");
- if (event_handler(ud) < 0)
- break;
- }
- return 0;
- }
- int usbip_start_eh(struct usbip_device *ud)
- {
- init_waitqueue_head(&ud->eh_waitq);
- ud->event = 0;
- ud->eh = kthread_run(event_handler_loop, ud, "usbip_eh");
- if (IS_ERR(ud->eh)) {
- pr_warn("Unable to start control thread\n");
- return PTR_ERR(ud->eh);
- }
- return 0;
- }
- EXPORT_SYMBOL_GPL(usbip_start_eh);
- void usbip_stop_eh(struct usbip_device *ud)
- {
- if (ud->eh == current)
- return; /* do not wait for myself */
- kthread_stop(ud->eh);
- usbip_dbg_eh("usbip_eh has finished\n");
- }
- EXPORT_SYMBOL_GPL(usbip_stop_eh);
- void usbip_event_add(struct usbip_device *ud, unsigned long event)
- {
- unsigned long flags;
- spin_lock_irqsave(&ud->lock, flags);
- ud->event |= event;
- wake_up(&ud->eh_waitq);
- spin_unlock_irqrestore(&ud->lock, flags);
- }
- EXPORT_SYMBOL_GPL(usbip_event_add);
- int usbip_event_happened(struct usbip_device *ud)
- {
- int happened = 0;
- unsigned long flags;
- spin_lock_irqsave(&ud->lock, flags);
- if (ud->event != 0)
- happened = 1;
- spin_unlock_irqrestore(&ud->lock, flags);
- return happened;
- }
- EXPORT_SYMBOL_GPL(usbip_event_happened);
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