• David Fries's avatar
    W1: fix deadlocks and remove w1_control_thread · c30c9b15
    David Fries authored
    
    w1_control_thread was removed which would wake up every second and process
    newly registered family codes and complete some final cleanup for a
    removed master.  Those routines were moved to the threads that were
    previously requesting those operations.  A new function
    w1_reconnect_slaves takes care of reconnecting existing slave devices when
    a new family code is registered or removed.  The removal case was missing
    and would cause a deadlock waiting for the family code reference count to
    decrease, which will now happen.  A problem with registering a family code
    was fixed.  A slave device would be unattached if it wasn't yet claimed,
    then attached at the end of the list, two unclaimed slaves would cause an
    infinite loop.
    
    The struct w1_bus_master.search now takes a pointer to the struct
    w1_master device to avoid searching for it, which would have caused a
    lock ordering deadlock with the removal of w1_control_thread.
    Signed-off-by: default avatarDavid Fries <david@fries.net>
    Signed-off-by: default avatarEvgeniy Polyakov <johnpol@2ka.mipt.ru>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    c30c9b15
w1_family.h 1.69 KB
/*
 *	w1_family.h
 *
 * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
 *
 *
 * This program 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 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 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 __W1_FAMILY_H
#define __W1_FAMILY_H

#include <linux/types.h>
#include <linux/device.h>
#include <asm/atomic.h>

#define W1_FAMILY_DEFAULT	0
#define W1_FAMILY_SMEM_01	0x01
#define W1_FAMILY_SMEM_81	0x81
#define W1_THERM_DS18S20 	0x10
#define W1_THERM_DS1822  	0x22
#define W1_EEPROM_DS2433  	0x23
#define W1_THERM_DS18B20 	0x28
#define W1_FAMILY_DS2760	0x30

#define MAXNAMELEN		32

struct w1_slave;

struct w1_family_ops
{
	int  (* add_slave)(struct w1_slave *);
	void (* remove_slave)(struct w1_slave *);
};

struct w1_family
{
	struct list_head	family_entry;
	u8			fid;

	struct w1_family_ops	*fops;

	atomic_t		refcnt;
	u8			need_exit;
};

extern spinlock_t w1_flock;

void w1_family_put(struct w1_family *);
void __w1_family_get(struct w1_family *);
struct w1_family * w1_family_registered(u8);
void w1_unregister_family(struct w1_family *);
int w1_register_family(struct w1_family *);

#endif /* __W1_FAMILY_H */