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From: Greg KH <gregkh@suse.de>
To: linux-kernel@vger.kernel.org
Cc: mochel@digitalimplant.org
Subject: [PATCH] Add a semaphore to struct device to synchronize calls to its driver.
Date: Mon, 20 Jun 2005 15:59:24 -0700	[thread overview]
Message-ID: <1119308364310@kroah.com> (raw)
In-Reply-To: <11193083641656@kroah.com>

[PATCH] Add a semaphore to struct device to synchronize calls to its driver.

This adds a per-device semaphore that is taken before every call from the core to a
driver method. This prevents e.g. simultaneous calls to the ->suspend() or ->resume()
and ->probe() or ->release(), potentially saving a whole lot of headaches.

It also moves us a step closer to removing the bus rwsem, since it protects the fields
in struct device that are modified by the core.

Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
commit af70316af182f4716cc5eec7e0d27fc731d164bd
tree 22fa4732c8270db8fd3f681355cd83e4b8088847
parent eb51b65005737b777e0709683b061d5f82aefd97
author mochel@digitalimplant.org <mochel@digitalimplant.org> Mon, 21 Mar 2005 10:41:04 -0800
committer Greg Kroah-Hartman <gregkh@suse.de> Mon, 20 Jun 2005 15:15:12 -0700

 drivers/base/bus.c           |   14 +++++++++++---
 drivers/base/core.c          |    1 +
 drivers/base/power/resume.c  |    8 ++++++--
 drivers/base/power/suspend.c |    3 ++-
 include/linux/device.h       |    4 ++++
 5 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -283,18 +283,22 @@ void device_bind_driver(struct device * 
  */
 int driver_probe_device(struct device_driver * drv, struct device * dev)
 {
+	int error = 0;
+
 	if (drv->bus->match && !drv->bus->match(dev, drv))
 		return -ENODEV;
 
+	down(&dev->sem);
 	dev->driver = drv;
 	if (drv->probe) {
-		int error = drv->probe(dev);
+		error = drv->probe(dev);
 		if (error) {
 			dev->driver = NULL;
+			up(&dev->sem);
 			return error;
 		}
 	}
-
+	up(&dev->sem);
 	device_bind_driver(dev);
 	return 0;
 }
@@ -385,7 +389,10 @@ void driver_attach(struct device_driver 
 
 void device_release_driver(struct device * dev)
 {
-	struct device_driver * drv = dev->driver;
+	struct device_driver * drv;
+
+	down(&dev->sem);
+	drv = dev->driver;
 	if (drv) {
 		sysfs_remove_link(&drv->kobj, kobject_name(&dev->kobj));
 		sysfs_remove_link(&dev->kobj, "driver");
@@ -394,6 +401,7 @@ void device_release_driver(struct device
 			drv->remove(dev);
 		dev->driver = NULL;
 	}
+	up(&dev->sem);
 }
 
 
diff --git a/drivers/base/core.c b/drivers/base/core.c
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -212,6 +212,7 @@ void device_initialize(struct device *de
 	INIT_LIST_HEAD(&dev->driver_list);
 	INIT_LIST_HEAD(&dev->bus_list);
 	INIT_LIST_HEAD(&dev->dma_pools);
+	init_MUTEX(&dev->sem);
 }
 
 /**
diff --git a/drivers/base/power/resume.c b/drivers/base/power/resume.c
--- a/drivers/base/power/resume.c
+++ b/drivers/base/power/resume.c
@@ -22,6 +22,9 @@ extern int sysdev_resume(void);
 
 int resume_device(struct device * dev)
 {
+	int error = 0;
+
+	down(&dev->sem);
 	if (dev->power.pm_parent
 			&& dev->power.pm_parent->power.power_state) {
 		dev_err(dev, "PM: resume from %d, parent %s still %d\n",
@@ -31,9 +34,10 @@ int resume_device(struct device * dev)
 	}
 	if (dev->bus && dev->bus->resume) {
 		dev_dbg(dev,"resuming\n");
-		return dev->bus->resume(dev);
+		error = dev->bus->resume(dev);
 	}
-	return 0;
+	up(&dev->sem);
+	return error;
 }
 
 
diff --git a/drivers/base/power/suspend.c b/drivers/base/power/suspend.c
--- a/drivers/base/power/suspend.c
+++ b/drivers/base/power/suspend.c
@@ -39,6 +39,7 @@ int suspend_device(struct device * dev, 
 {
 	int error = 0;
 
+	down(&dev->sem);
 	if (dev->power.power_state) {
 		dev_dbg(dev, "PM: suspend %d-->%d\n",
 			dev->power.power_state, state);
@@ -58,7 +59,7 @@ int suspend_device(struct device * dev, 
 		dev_dbg(dev, "suspending\n");
 		error = dev->bus->suspend(dev, state);
 	}
-
+	up(&dev->sem);
 	return error;
 }
 
diff --git a/include/linux/device.h b/include/linux/device.h
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -264,6 +264,10 @@ struct device {
 	struct kobject kobj;
 	char	bus_id[BUS_ID_SIZE];	/* position on parent bus */
 
+	struct semaphore	sem;	/* semaphore to synchronize calls to
+					 * its driver.
+					 */
+
 	struct bus_type	* bus;		/* type of bus device is on */
 	struct device_driver *driver;	/* which driver has allocated this
 					   device */


  reply	other threads:[~2005-06-21  2:51 UTC|newest]

Thread overview: 92+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-06-20 22:55 [GIT PATCH] Driver core changes for 2.6.12 Greg KH
2005-06-20 22:59 ` [PATCH] sysfs_{create|remove}_link should take const char * Greg KH
2005-06-20 22:59   ` [PATCH] kobject_hotplug() should use kobject_name() Greg KH
2005-06-20 22:59     ` [PATCH] Make kobject's name be const char * Greg KH
2005-06-20 22:59       ` [PATCH] kset_hotplug_ops->name shoudl return " Greg KH
2005-06-20 22:59         ` [PATCH] make driver's name be " Greg KH
2005-06-20 22:59           ` [PATCH] Make attributes names " Greg KH
2005-06-20 22:59             ` [PATCH] sysfs: (driver/base) if show/store is missing return -EIO Greg KH
2005-06-20 22:59               ` [PATCH] sysfs: " Greg KH
2005-06-20 22:59                 ` [PATCH] sysfs: (driver/pci) " Greg KH
2005-06-20 22:59                   ` [PATCH] sysfs: (driver/block) " Greg KH
2005-06-20 22:59                     ` [PATCH] sysfs: (rest) " Greg KH
2005-06-20 22:59                       ` [PATCH] INPUT: move to use the new class code, instead of class_simple Greg KH
2005-06-20 22:59                         ` [PATCH] tty: " Greg KH
2005-06-20 22:59                           ` [PATCH] CLASS: move a "simple" class logic into the class core Greg KH
2005-06-20 22:59                             ` [PATCH] class: convert sound/* to use the new class api instead of class_simple Greg KH
2005-06-20 22:59                               ` [PATCH] USB: move the usb hcd code to use the new class code Greg KH
2005-06-20 22:59                                 ` [PATCH] class: convert drivers/block/* to use the new class api instead of class_simple Greg KH
2005-06-20 22:59                                   ` [PATCH] class: convert drivers/ieee1394/* " Greg KH
2005-06-20 22:59                                     ` [PATCH] class: convert drivers/char/* " Greg KH
2005-06-20 22:59                                       ` [PATCH] class: convert drivers/scsi/* " Greg KH
2005-06-20 22:59                                         ` [PATCH] class: convert drivers/* " Greg KH
2005-06-20 22:59                                           ` [PATCH] USB: trivial error path fix Greg KH
2005-06-20 22:59                                             ` [PATCH] class: convert arch/* to use the new class api instead of class_simple Greg KH
2005-06-20 22:59                                               ` [PATCH] class: convert the remaining class_simple users in the kernel to usee the new class api Greg KH
2005-06-20 22:59                                                 ` [PATCH] class: add kerneldoc for the new class functions Greg KH
2005-06-20 22:59                                                   ` [PATCH] class: remove class_simple code, as no one in the tree is using it anymore Greg KH
2005-06-20 22:59                                                     ` [PATCH] fix "make mandocs" after class_simple.c removal Greg KH
2005-06-20 22:59                                                       ` Greg KH [this message]
2005-06-20 22:59                                                         ` [PATCH] fix up ipmi code " Greg KH
2005-06-20 22:59                                                           ` [PATCH] Move device/driver code to drivers/base/dd.c Greg KH
2005-06-20 22:59                                                             ` [PATCH] Use driver_for_each_device() instead of manually walking list Greg KH
2005-06-20 22:59                                                               ` [PATCH] Use driver_for_each_device() in drivers/pnp/driver.c " Greg KH
2005-06-20 22:59                                                                 ` [PATCH] Add driver_for_each_device() Greg KH
2005-06-20 22:59                                                                   ` [PATCH] Add a klist to struct bus_type for its drivers Greg KH
2005-06-20 22:59                                                                     ` [PATCH] Add a klist to struct bus_type for its devices Greg KH
2005-06-20 22:59                                                                       ` [PATCH] Add initial implementation of klist helpers Greg KH
2005-06-20 22:59                                                                         ` [PATCH] Add a klist to struct device_driver for the devices bound to it Greg KH
2005-06-20 22:59                                                                           ` [PATCH] Remove the unused device_find() Greg KH
2005-06-20 22:59                                                                             ` [PATCH] Use bus_for_each_{dev,drv} for driver binding Greg KH
2005-06-20 22:59                                                                               ` [PATCH] add klist_node_attached() to determine if a node is on a list or not Greg KH
2005-06-20 22:59                                                                                 ` [PATCH] Fix up USB to use klist_node_attached() instead of list_empty() on lists that will go away Greg KH
2005-06-20 22:59                                                                                   ` [PATCH] Remove struct device::driver_list Greg KH
2005-06-20 22:59                                                                                     ` [PATCH] Fix up bus code and remove use of rwsem Greg KH
2005-06-20 22:59                                                                                       ` [PATCH] Remove struct device::bus_list Greg KH
2005-06-20 22:59                                                                                         ` [PATCH] Don't reference NULL klist pointer in klist_remove() Greg KH
2005-06-20 22:59                                                                                           ` [PATCH] Call klist_del() instead of klist_remove() Greg KH
2005-06-20 22:59                                                                                             ` [PATCH] Use device_for_each_child() to unregister devices in scsi_remove_target() Greg KH
2005-06-20 22:59                                                                                               ` [PATCH] use device_for_each_child() to properly access child devices Greg KH
2005-06-20 22:59                                                                                                 ` [PATCH] Use a klist for device child lists Greg KH
2005-06-20 22:59                                                                                                   ` [PATCH] Fix up bogus comment Greg KH
2005-06-20 22:59                                                                                                     ` [PATCH] driver core: change export symbol for driver_for_each_device() Greg KH
2005-06-20 22:59                                                                                                       ` [PATCH] Use device_for_each_child() to unregister devices in nodemgr_remove_host_dev() Greg KH
2005-06-20 22:59                                                                                                         ` [PATCH] use device_for_each_child() to properly access child devices Greg KH
2005-06-20 22:59                                                                                                           ` [PATCH] USB: fix build warning in usb core as pointed out by Andrew Greg KH
2005-06-20 22:59                                                                                                             ` [PATCH] Driver Core: fix bk-driver-core kills ppc64 Greg KH
2005-06-20 22:59                                                                                                               ` [PATCH] Fix typo in scdrv_init() Greg KH
2005-06-20 22:59                                                                                                                 ` [PATCH] Driver core: Fix up the driver and device iterators to be quieter Greg KH
2005-06-20 22:59                                                                                                                   ` [PATCH] usb: klist_node_attached() fix Greg KH
2005-06-20 22:59                                                                                                                     ` [PATCH] sn: fixes due to driver core changes Greg KH
2005-06-20 22:59                                                                                                                       ` [PATCH] driver core: Fix races in driver_detach() Greg KH
2005-06-20 22:59                                                                                                                         ` [PATCH] Driver Core: driver model doc update Greg KH
2005-06-20 22:59                                                                                                                           ` [PATCH] Driver core: unregister_node() for hotplug use Greg KH
2005-06-20 22:59                                                                                                                             ` [PATCH] usbcore: Don't call device_release_driver recursively Greg KH
2005-06-20 22:59                                                                                                                               ` [PATCH] libfs: add simple attribute files Greg KH
2005-06-20 22:59                                                                                                                                 ` [PATCH] Driver core: change device_attribute callbacks Greg KH
2005-06-20 22:59                                                                                                                                   ` [PATCH] driver core: fix error handling in bus_add_device Greg KH
2005-06-20 22:59                                                                                                                                     ` [PATCH] Driver core: Documentation: update device attribute callbacks Greg KH
2005-06-20 22:59                                                                                                                                       ` [PATCH] Driver Core: drivers/base - drivers/i2c/chips/adm1026.c: " Greg KH
2005-06-20 22:59                                                                                                                                         ` [PATCH] Driver Core: arch: " Greg KH
2005-06-20 22:59                                                                                                                                           ` [PATCH] Driver Core: drivers/i2c/chips/adm1031.c - lm75.c: " Greg KH
2005-06-20 22:59                                                                                                                                             ` [PATCH] Driver Core: drivers/i2c/chips/lm77.c - max1619.c: " Greg KH
2005-06-20 22:59                                                                                                                                               ` [PATCH] Driver Core: drivers/i2c/chips/pc87360.c - w83627hf.c: " Greg KH
2005-06-20 22:59                                                                                                                                                 ` [PATCH] Driver Core: drivers/char/raw3270.c - drivers/net/netiucv.c: " Greg KH
2005-06-20 22:59                                                                                                                                                   ` [PATCH] Driver Core: drivers/i2c/chips/w83781d.c - drivers/s390/block/dcssblk.c: " Greg KH
2005-06-20 22:59                                                                                                                                                     ` [PATCH] Driver Core: drivers/usb/input/aiptek.c - drivers/zorro/zorro-sysfs.c: " Greg KH
2005-06-20 22:59                                                                                                                                                       ` [PATCH] Driver Core: drivers/s390/net/qeth_sys.c - drivers/usb/gadget/pxa2xx_udc.c: " Greg KH
2005-06-20 22:59                                                                                                                                                         ` [PATCH] Driver Core: include: " Greg KH
2005-06-20 22:59                                                                                                                                                           ` [PATCH] I2C: drivers/i2c/chips/adm1026.c: use dynamic sysfs callbacks Greg KH
2005-06-20 22:59                                                                                                                                                             ` [PATCH] I2C: add i2c sensor_device_attribute and macros Greg KH
2005-06-20 22:59                                                                                                                                                               ` [PATCH] sysfs-iattr: attach sysfs_dirent before new inode Greg KH
2005-06-20 22:59                                                                                                                                                                 ` [PATCH] Driver core: Don't "lose" devices on suspend on failure Greg KH
2005-06-20 22:59                                                                                                                                                                   ` [PATCH] sysfs-iattr: set inode attributes Greg KH
2005-06-20 22:59                                                                                                                                                                     ` [PATCH] sysfs-iattr: add sysfs_setattr Greg KH
2005-06-20 22:59                                                                                                                                                                       ` [PATCH] SYSFS: fix PAGE_SIZE check Greg KH
2005-06-20 22:59                                                                                                                                                                         ` [PATCH] USB: fix show_modalias() function due to attribute change Greg KH
2005-06-20 22:59                                                                                                                                                                           ` [PATCH] PCI: " Greg KH
2005-07-06  0:38                                                                                               ` [PATCH] Use device_for_each_child() to unregister devices in scsi_remove_target() Patrick Mansfield
2005-07-12  0:20                                                                                                 ` Greg KH
2005-07-12  0:56                                                                                                   ` Patrick Mansfield
2005-06-21 11:42                                                                         ` [PATCH] Add initial implementation of klist helpers Rik van Riel
2005-06-21 23:13                                                                           ` Greg KH

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