forked from Minki/linux
21619792d1
Change spin_lock calls to spin_lock_irqsave to prevent attmpted recursive lock taking in interrupt context. This patch fixes Bug 109351 https://bugzilla.kernel.org/show_bug.cgi?id=109351 Signed-off-by: Andrew Goodbody <andrew.goodbody@cambrionix.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
130 lines
2.9 KiB
C
130 lines
2.9 KiB
C
/*
|
|
* 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);
|