mirror of
https://github.com/torvalds/linux.git
synced 2024-11-08 13:11:45 +00:00
30ad64b8ac
Since most dvb ioctls wrap their real work with dvb_usercopy, the static mutex
used in dvb_usercopy effectively is a global lock for dvb ioctls.
Unfortunately, frontend ioctls can be blocked by the frontend thread for
several seconds; this leads to unacceptable lock contention. Mitigate that by
pushing the mutex from dvb_usercopy down to the individual, device specific
ioctls.
There are 10 such ioctl functions using dvb_usercopy, either calling it
directly, or via the trivial wrapper dvb_generic_ioctl. The following already
employ their own locking and look safe:
• dvb_demux_ioctl (as per dvb_demux_do_ioctl)
• dvb_dvr_ioctl (as per dvb_dvr_do_ioctl)
• dvb_osd_ioctl (as per single non-trivial callee)
• fdtv_ca_ioctl (as per callees)
• dvb_frontend_ioctl
The following functions do not, and are thus changed to use a device specific
mutex:
• dvb_net_ioctl (as per dvb_net_do_ioctl)
• dvb_ca_en50221_io_ioctl (as per dvb_ca_en50221_io_do_ioctl)
• dvb_video_ioctl
• dvb_audio_ioctl
• dvb_ca_ioctl
Signed-off-by: Nikolaus Schulz <schulz@macnetix.de>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
68 lines
1.7 KiB
C
68 lines
1.7 KiB
C
/*
|
|
* dvb_net.h
|
|
*
|
|
* Copyright (C) 2001 Ralph Metzler for convergence integrated media GmbH
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public License
|
|
* as published by the Free Software Foundation; either version 2.1
|
|
* of the License, or (at your option) any later version.
|
|
*
|
|
* This program 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 Lesser 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.
|
|
*
|
|
*/
|
|
|
|
#ifndef _DVB_NET_H_
|
|
#define _DVB_NET_H_
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/netdevice.h>
|
|
#include <linux/inetdevice.h>
|
|
#include <linux/etherdevice.h>
|
|
#include <linux/skbuff.h>
|
|
|
|
#include "dvbdev.h"
|
|
|
|
#define DVB_NET_DEVICES_MAX 10
|
|
|
|
#ifdef CONFIG_DVB_NET
|
|
|
|
struct dvb_net {
|
|
struct dvb_device *dvbdev;
|
|
struct net_device *device[DVB_NET_DEVICES_MAX];
|
|
int state[DVB_NET_DEVICES_MAX];
|
|
unsigned int exit:1;
|
|
struct dmx_demux *demux;
|
|
struct mutex ioctl_mutex;
|
|
};
|
|
|
|
void dvb_net_release(struct dvb_net *);
|
|
int dvb_net_init(struct dvb_adapter *, struct dvb_net *, struct dmx_demux *);
|
|
|
|
#else
|
|
|
|
struct dvb_net {
|
|
struct dvb_device *dvbdev;
|
|
};
|
|
|
|
static inline void dvb_net_release(struct dvb_net *dvbnet)
|
|
{
|
|
}
|
|
|
|
static inline int dvb_net_init(struct dvb_adapter *adap,
|
|
struct dvb_net *dvbnet, struct dmx_demux *dmx)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
#endif /* ifdef CONFIG_DVB_NET */
|
|
|
|
#endif
|