Commit 533354d4 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Linus Torvalds
Browse files

Misc: Add possibility to remove misc devices during suspend/resume 



Make it possible to unregister a misc device object in a safe way during a
suspend/resume cycle.

Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Cc: Michael Buesch <mb@bu3sch.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <greg@kroah.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f011e2e2

drivers/char/misc.c

+9 −4
Original line number Diff line number Diff line
@@ -232,8 +232,9 @@ int misc_register(struct miscdevice * misc) 
}



/**

 *	misc_deregister - unregister a miscellaneous device

 *	__misc_deregister - unregister a miscellaneous device

 *	@misc: device to unregister

 *	@suspended: to be set if the function is used during suspend/resume

 *

 *	Unregister a miscellaneous device that was previously

 *	successfully registered with misc_register(). Success
@@ -241,7 +242,7 @@ int misc_register(struct miscdevice * misc) 
 *	indicates an error.

 */



int misc_deregister(struct miscdevice * misc)

int __misc_deregister(struct miscdevice *misc, bool suspended)

{

	int i = misc->minor;
@@ -250,6 +251,10 @@ int misc_deregister(struct miscdevice * misc) 


	mutex_lock(&misc_mtx);

	list_del(&misc->list);

	if (suspended)

		destroy_suspended_device(misc_class,

					MKDEV(MISC_MAJOR, misc->minor));

	else

		device_destroy(misc_class, MKDEV(MISC_MAJOR, misc->minor));

	if (i < DYNAMIC_MINORS && i>0) {

		misc_minors[i>>3] &= ~(1 << (misc->minor & 7));
@@ -259,7 +264,7 @@ int misc_deregister(struct miscdevice * misc) 
}



EXPORT_SYMBOL(misc_register);

EXPORT_SYMBOL(misc_deregister);

EXPORT_SYMBOL(__misc_deregister);



static int __init misc_init(void)

{

include/linux/miscdevice.h

+9 −1
Original line number Diff line number Diff line
@@ -43,7 +43,15 @@ struct miscdevice { 
};



extern int misc_register(struct miscdevice * misc);

extern int misc_deregister(struct miscdevice * misc);

extern int __misc_deregister(struct miscdevice *misc, bool suspended);

static inline int misc_deregister(struct miscdevice *misc)

{

	return __misc_deregister(misc, false);

}

static inline int misc_deregister_suspended(struct miscdevice *misc)

{

	return __misc_deregister(misc, true);

}



#define MODULE_ALIAS_MISCDEV(minor)				\

	MODULE_ALIAS("char-major-" __stringify(MISC_MAJOR)	\

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