From ddd5d35a8f7c1924049e8b6877b3177c1787e6a3 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Thu, 10 Aug 2006 01:18:18 -0400 Subject: class_device_create(): make fmt argument 'const char *' Signed-off-by: Dmitry Torokhov Signed-off-by: Greg Kroah-Hartman --- include/linux/device.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index 1e5f30da98bc..1fec28546525 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -277,7 +277,7 @@ extern struct class_device *class_device_create(struct class *cls, struct class_device *parent, dev_t devt, struct device *device, - char *fmt, ...) + const char *fmt, ...) __attribute__((format(printf,5,6))); extern void class_device_destroy(struct class *cls, dev_t devt); -- cgit v1.2.3 From 5cbe5f8a5897470698222ac9924429056e57d84c Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Thu, 10 Aug 2006 01:19:19 -0400 Subject: device_create(): make fmt argument 'const char *' Signed-off-by: Greg Kroah-Hartman --- include/linux/device.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index 1fec28546525..8d92013f9ce1 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -384,7 +384,7 @@ extern void device_reprobe(struct device *dev); * Easy functions for dynamically creating devices on the fly */ extern struct device *device_create(struct class *cls, struct device *parent, - dev_t devt, char *fmt, ...) + dev_t devt, const char *fmt, ...) __attribute__((format(printf,4,5))); extern void device_destroy(struct class *cls, dev_t devt); -- cgit v1.2.3 From ab7d7371acc68fa9130b079a9ba879191202035f Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Sandonis Date: Wed, 13 Sep 2006 15:34:05 +0200 Subject: Driver core: add const to class_create Adds const to class_create second parameter, because: struct class { const char * name; /*...*/ } Signed-off-by: Miguel Ojeda Sandonis Signed-off-by: Greg Kroah-Hartman --- include/linux/device.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index 8d92013f9ce1..8a648cd94fa9 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -271,7 +271,7 @@ struct class_interface { extern int class_interface_register(struct class_interface *); extern void class_interface_unregister(struct class_interface *); -extern struct class *class_create(struct module *owner, char *name); +extern struct class *class_create(struct module *owner, const char *name); extern void class_destroy(struct class *cls); extern struct class_device *class_device_create(struct class *cls, struct class_device *parent, -- cgit v1.2.3 From 7c8265f51073bc8632a99de78d5fd19117ed78b7 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 24 Jun 2006 14:50:29 -0700 Subject: Suspend infrastructure cleanup and extension Allow devices to participate in the suspend process more intimately, in particular, allow the final phase (with interrupts disabled) to also be open to normal devices, not just system devices. Also, allow classes to participate in device suspend. Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- include/linux/device.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index 8a648cd94fa9..b40be6fca6fa 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -51,8 +51,12 @@ struct bus_type { int (*probe)(struct device * dev); int (*remove)(struct device * dev); void (*shutdown)(struct device * dev); - int (*suspend)(struct device * dev, pm_message_t state); - int (*resume)(struct device * dev); + + int (*suspend_prepare)(struct device * dev, pm_message_t state); + int (*suspend)(struct device * dev, pm_message_t state); + int (*suspend_late)(struct device * dev, pm_message_t state); + int (*resume_early)(struct device * dev); + int (*resume)(struct device * dev); }; extern int bus_register(struct bus_type * bus); @@ -154,6 +158,9 @@ struct class { void (*release)(struct class_device *dev); void (*class_release)(struct class *class); + + int (*suspend)(struct device *, pm_message_t state); + int (*resume)(struct device *); }; extern int class_register(struct class *); -- cgit v1.2.3 From 1d3a82af45428c5e8deaa119cdeb79611ae46371 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Wed, 30 Aug 2006 14:09:47 -0700 Subject: PM: no suspend_prepare() phase Remove the new suspend_prepare() phase. It doesn't seem very usable, has never been tested, doesn't address fault cleanup, and would need a sibling resume_complete(); plus there are no real use cases. It could be restored later if those issues get resolved. Signed-off-by: David Brownell Cc: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- include/linux/device.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index b40be6fca6fa..b3646462d6dc 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -52,7 +52,6 @@ struct bus_type { int (*remove)(struct device * dev); void (*shutdown)(struct device * dev); - int (*suspend_prepare)(struct device * dev, pm_message_t state); int (*suspend)(struct device * dev, pm_message_t state); int (*suspend_late)(struct device * dev, pm_message_t state); int (*resume_early)(struct device * dev); -- cgit v1.2.3 From de0ff00d723fd821d372496e2c084805644aa5e1 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Tue, 27 Jun 2006 00:06:09 -0700 Subject: Driver core: add groups support to struct device This is needed for the network class devices in order to be able to convert over to use struct device. Signed-off-by: Greg Kroah-Hartman --- include/linux/device.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index b3646462d6dc..994d3ebd53f4 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -344,6 +344,7 @@ struct device { struct list_head node; struct class *class; /* optional*/ dev_t devt; /* dev_t, creates the sysfs "dev" */ + struct attribute_group **groups; /* optional groups */ void (*release)(struct device * dev); }; -- cgit v1.2.3 From 2620efef7029bb040430f50f0fc148f2d5e002ad Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Wed, 28 Jun 2006 16:19:58 -0700 Subject: Driver core: add ability for classes to handle devices properly This adds two new callbacks to the class structure: int (*dev_uevent)(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size); void (*dev_release)(struct device *dev); And one pointer: struct device_attribute * dev_attrs; which all corrispond with the same thing as the "normal" class devices do, yet this is for when a struct device is bound to a class. Someday soon, struct class_device will go away, and then the other fields in this structure can be removed too. But this is necessary in order to get the transition to work properly. Tested out on a network core patch that converted it to use struct device instead of struct class_device. Signed-off-by: Greg Kroah-Hartman --- include/linux/device.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index 994d3ebd53f4..3122bd25ce42 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -151,12 +151,16 @@ struct class { struct class_attribute * class_attrs; struct class_device_attribute * class_dev_attrs; + struct device_attribute * dev_attrs; int (*uevent)(struct class_device *dev, char **envp, int num_envp, char *buffer, int buffer_size); + int (*dev_uevent)(struct device *dev, char **envp, int num_envp, + char *buffer, int buffer_size); void (*release)(struct class_device *dev); void (*class_release)(struct class *class); + void (*dev_release)(struct device *dev); int (*suspend)(struct device *, pm_message_t state); int (*resume)(struct device *); -- cgit v1.2.3 From a2de48cace5d0993da6cfa28b276ae724dc3569b Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Mon, 3 Jul 2006 14:31:12 -0700 Subject: Driver core: add device_rename function The network layer needs this to convert to using struct device instead of a struct class_device. Signed-off-by: Greg Kroah-Hartman --- include/linux/device.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index 3122bd25ce42..3400e09bf458 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -380,6 +380,7 @@ extern int device_add(struct device * dev); extern void device_del(struct device * dev); extern int device_for_each_child(struct device *, void *, int (*fn)(struct device *, void *)); +extern int device_rename(struct device *dev, char *new_name); /* * Manual binding of a device to driver. See drivers/base/bus.c -- cgit v1.2.3 From c205ef4880273d2de4ee5388d4e52227ff688cc4 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Mon, 7 Aug 2006 22:19:37 -0700 Subject: Driver core: create devices/virtual/ tree This change creates a devices/virtual/CLASS_NAME tree for struct devices that belong to a class, yet do not have a "real" struct device for a parent. It automatically creates the directories on the fly as needed. Cc: Kay Sievers Signed-off-by: Greg Kroah-Hartman --- include/linux/device.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index 3400e09bf458..bbb0d6b5d232 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -149,6 +149,8 @@ struct class { struct list_head interfaces; struct semaphore sem; /* locks both the children and interfaces lists */ + struct kobject *virtual_dir; + struct class_attribute * class_attrs; struct class_device_attribute * class_dev_attrs; struct device_attribute * dev_attrs; @@ -291,7 +293,6 @@ extern struct class_device *class_device_create(struct class *cls, __attribute__((format(printf,5,6))); extern void class_device_destroy(struct class *cls, dev_t devt); - /* interface for exporting device attributes */ struct device_attribute { struct attribute attr; @@ -400,6 +401,8 @@ extern struct device *device_create(struct class *cls, struct device *parent, __attribute__((format(printf,4,5))); extern void device_destroy(struct class *cls, dev_t devt); +extern int virtual_device_parent(struct device *dev); + /* * Platform "fixup" functions - allow the platform to have their say * about devices and actions that the general device layer doesn't -- cgit v1.2.3 From c47ed219ba81632595e9f02e27318151fec16c9e Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Wed, 13 Sep 2006 15:34:05 +0200 Subject: Class: add support for class interfaces for devices When moving class_device usage over to device, we need to handle class_interfaces properly with devices. This patch adds that support. Signed-off-by: Greg Kroah-Hartman --- include/linux/device.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index bbb0d6b5d232..e0fae0e76fa9 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -278,6 +278,8 @@ struct class_interface { int (*add) (struct class_device *, struct class_interface *); void (*remove) (struct class_device *, struct class_interface *); + int (*add_dev) (struct device *, struct class_interface *); + void (*remove_dev) (struct device *, struct class_interface *); }; extern int class_interface_register(struct class_interface *); -- cgit v1.2.3 From 2589f1887b0bf9f08ec3d7f3c5705ccb7c628076 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Tue, 19 Sep 2006 09:39:19 -0700 Subject: Driver core: add ability for devices to create and remove bin files Makes it easier for devices to create and remove binary attribute files so they don't have to call directly into sysfs. This is needed to help with the conversion from struct class_device to struct device. Signed-off-by: Greg Kroah-Hartman --- include/linux/device.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index e0fae0e76fa9..7d447d7271c5 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -309,6 +309,10 @@ struct device_attribute dev_attr_##_name = __ATTR(_name,_mode,_show,_store) extern int device_create_file(struct device *device, struct device_attribute * entry); extern void device_remove_file(struct device * dev, struct device_attribute * attr); +extern int __must_check device_create_bin_file(struct device *dev, + struct bin_attribute *attr); +extern void device_remove_bin_file(struct device *dev, + struct bin_attribute *attr); struct device { struct klist klist_children; struct klist_node knode_parent; /* node in sibling list */ -- cgit v1.2.3 From 4a7fb6363f2d1a6c09a10253937f672f3c7929e1 Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Mon, 14 Aug 2006 22:43:17 -0700 Subject: add __must_check to device management code We're getting a lot of crashes in the sysfs/kobject/device/bus/class code and they're very hard to diagnose. I'm suspecting that in some cases this is because drivers aren't checking return values and aren't handling errors correctly. So the code blithely blunders on and crashes later in very obscure ways. There's just no reason to ignore errors which can and do occur. So the patch sprinkles __must_check all over these APIs. Causes 1,513 new warnings. Heh. Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- include/linux/device.h | 52 +++++++++++++++++++++++++++----------------------- 1 file changed, 28 insertions(+), 24 deletions(-) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index 7d447d7271c5..ad4db72f5733 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -58,7 +59,7 @@ struct bus_type { int (*resume)(struct device * dev); }; -extern int bus_register(struct bus_type * bus); +extern int __must_check bus_register(struct bus_type * bus); extern void bus_unregister(struct bus_type * bus); extern void bus_rescan_devices(struct bus_type * bus); @@ -70,9 +71,9 @@ int bus_for_each_dev(struct bus_type * bus, struct device * start, void * data, struct device * bus_find_device(struct bus_type *bus, struct device *start, void *data, int (*match)(struct device *, void *)); -int bus_for_each_drv(struct bus_type * bus, struct device_driver * start, - void * data, int (*fn)(struct device_driver *, void *)); - +int __must_check bus_for_each_drv(struct bus_type *bus, + struct device_driver *start, void *data, + int (*fn)(struct device_driver *, void *)); /* driverfs interface for exporting bus attributes */ @@ -85,7 +86,8 @@ struct bus_attribute { #define BUS_ATTR(_name,_mode,_show,_store) \ struct bus_attribute bus_attr_##_name = __ATTR(_name,_mode,_show,_store) -extern int bus_create_file(struct bus_type *, struct bus_attribute *); +extern int __must_check bus_create_file(struct bus_type *, + struct bus_attribute *); extern void bus_remove_file(struct bus_type *, struct bus_attribute *); struct device_driver { @@ -107,14 +109,13 @@ struct device_driver { }; -extern int driver_register(struct device_driver * drv); +extern int __must_check driver_register(struct device_driver * drv); extern void driver_unregister(struct device_driver * drv); extern struct device_driver * get_driver(struct device_driver * drv); extern void put_driver(struct device_driver * drv); extern struct device_driver *driver_find(const char *name, struct bus_type *bus); - /* driverfs interface for exporting driver attributes */ struct driver_attribute { @@ -126,16 +127,17 @@ struct driver_attribute { #define DRIVER_ATTR(_name,_mode,_show,_store) \ struct driver_attribute driver_attr_##_name = __ATTR(_name,_mode,_show,_store) -extern int driver_create_file(struct device_driver *, struct driver_attribute *); +extern int __must_check driver_create_file(struct device_driver *, + struct driver_attribute *); extern void driver_remove_file(struct device_driver *, struct driver_attribute *); -extern int driver_for_each_device(struct device_driver * drv, struct device * start, - void * data, int (*fn)(struct device *, void *)); +extern int __must_check driver_for_each_device(struct device_driver * drv, + struct device *start, void *data, + int (*fn)(struct device *, void *)); struct device * driver_find_device(struct device_driver *drv, struct device *start, void *data, int (*match)(struct device *, void *)); - /* * device classes */ @@ -168,7 +170,7 @@ struct class { int (*resume)(struct device *); }; -extern int class_register(struct class *); +extern int __must_check class_register(struct class *); extern void class_unregister(struct class *); @@ -181,7 +183,8 @@ struct class_attribute { #define CLASS_ATTR(_name,_mode,_show,_store) \ struct class_attribute class_attr_##_name = __ATTR(_name,_mode,_show,_store) -extern int class_create_file(struct class *, const struct class_attribute *); +extern int __must_check class_create_file(struct class *, + const struct class_attribute *); extern void class_remove_file(struct class *, const struct class_attribute *); struct class_device_attribute { @@ -194,7 +197,7 @@ struct class_device_attribute { struct class_device_attribute class_device_attr_##_name = \ __ATTR(_name,_mode,_show,_store) -extern int class_device_create_file(struct class_device *, +extern int __must_check class_device_create_file(struct class_device *, const struct class_device_attribute *); /** @@ -254,10 +257,10 @@ class_set_devdata (struct class_device *dev, void *data) } -extern int class_device_register(struct class_device *); +extern int __must_check class_device_register(struct class_device *); extern void class_device_unregister(struct class_device *); extern void class_device_initialize(struct class_device *); -extern int class_device_add(struct class_device *); +extern int __must_check class_device_add(struct class_device *); extern void class_device_del(struct class_device *); extern int class_device_rename(struct class_device *, char *); @@ -267,7 +270,7 @@ extern void class_device_put(struct class_device *); extern void class_device_remove_file(struct class_device *, const struct class_device_attribute *); -extern int class_device_create_bin_file(struct class_device *, +extern int __must_check class_device_create_bin_file(struct class_device *, struct bin_attribute *); extern void class_device_remove_bin_file(struct class_device *, struct bin_attribute *); @@ -282,7 +285,7 @@ struct class_interface { void (*remove_dev) (struct device *, struct class_interface *); }; -extern int class_interface_register(struct class_interface *); +extern int __must_check class_interface_register(struct class_interface *); extern void class_interface_unregister(struct class_interface *); extern struct class *class_create(struct module *owner, const char *name); @@ -307,7 +310,8 @@ struct device_attribute { #define DEVICE_ATTR(_name,_mode,_show,_store) \ struct device_attribute dev_attr_##_name = __ATTR(_name,_mode,_show,_store) -extern int device_create_file(struct device *device, struct device_attribute * entry); +extern int __must_check device_create_file(struct device *device, + struct device_attribute * entry); extern void device_remove_file(struct device * dev, struct device_attribute * attr); extern int __must_check device_create_bin_file(struct device *dev, struct bin_attribute *attr); @@ -380,12 +384,12 @@ static inline int device_is_registered(struct device *dev) /* * High level routines for use by the bus drivers */ -extern int device_register(struct device * dev); +extern int __must_check device_register(struct device * dev); extern void device_unregister(struct device * dev); extern void device_initialize(struct device * dev); -extern int device_add(struct device * dev); +extern int __must_check device_add(struct device * dev); extern void device_del(struct device * dev); -extern int device_for_each_child(struct device *, void *, +extern int __must_check device_for_each_child(struct device *, void *, int (*fn)(struct device *, void *)); extern int device_rename(struct device *dev, char *new_name); @@ -395,7 +399,7 @@ extern int device_rename(struct device *dev, char *new_name); */ extern void device_bind_driver(struct device * dev); extern void device_release_driver(struct device * dev); -extern int device_attach(struct device * dev); +extern int __must_check device_attach(struct device * dev); extern void driver_attach(struct device_driver * drv); extern void device_reprobe(struct device *dev); @@ -433,7 +437,7 @@ extern void device_shutdown(void); /* drivers/base/firmware.c */ -extern int firmware_register(struct subsystem *); +extern int __must_check firmware_register(struct subsystem *); extern void firmware_unregister(struct subsystem *); /* debugging and troubleshooting/diagnostic helpers. */ -- cgit v1.2.3 From f86db396ff455ed586751d21816a1ebd431264e5 Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Mon, 14 Aug 2006 22:43:20 -0700 Subject: drivers/base: check errors Add lots of return-value checking. : fix bus_rescan_devices()] Cc: "Randy.Dunlap" Signed-off-by: Cornelia Huck Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- include/linux/device.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index ad4db72f5733..b3da9a870cfc 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -62,7 +62,7 @@ struct bus_type { extern int __must_check bus_register(struct bus_type * bus); extern void bus_unregister(struct bus_type * bus); -extern void bus_rescan_devices(struct bus_type * bus); +extern int __must_check bus_rescan_devices(struct bus_type * bus); /* iterator helpers for buses */ @@ -397,11 +397,11 @@ extern int device_rename(struct device *dev, char *new_name); * Manual binding of a device to driver. See drivers/base/bus.c * for information on use. */ -extern void device_bind_driver(struct device * dev); +extern int __must_check device_bind_driver(struct device *dev); extern void device_release_driver(struct device * dev); extern int __must_check device_attach(struct device * dev); -extern void driver_attach(struct device_driver * drv); -extern void device_reprobe(struct device *dev); +extern int __must_check driver_attach(struct device_driver *drv); +extern int __must_check device_reprobe(struct device *dev); /* * Easy functions for dynamically creating devices on the fly -- cgit v1.2.3 From d779249ed4cb3b50690de6de8448829d65a1cd08 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Tue, 18 Jul 2006 10:59:59 -0700 Subject: Driver Core: add ability for drivers to do a threaded probe This adds the infrastructure for drivers to do a threaded probe, and waits at init time for all currently outstanding probes to complete. A new kernel thread will be created when the probe() function for the driver is called, if the multithread_probe bit is set in the driver saying it can support this kind of operation. I have tested this with USB and PCI, and it works, and shaves off a lot of time in the boot process, but there are issues with finding root boot disks, and some USB drivers assume that this can never happen, so it is currently not enabled for any bus type. Individual drivers can enable this right now if they wish, and bus authors can selectivly turn it on as well, once they determine that their subsystem will work properly with it. Signed-off-by: Greg Kroah-Hartman --- include/linux/device.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index b3da9a870cfc..74246efba931 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -106,6 +106,8 @@ struct device_driver { void (*shutdown) (struct device * dev); int (*suspend) (struct device * dev, pm_message_t state); int (*resume) (struct device * dev); + + unsigned int multithread_probe:1; }; @@ -115,6 +117,7 @@ extern void driver_unregister(struct device_driver * drv); extern struct device_driver * get_driver(struct device_driver * drv); extern void put_driver(struct device_driver * drv); extern struct device_driver *driver_find(const char *name, struct bus_type *bus); +extern int driver_probe_done(void); /* driverfs interface for exporting driver attributes */ -- cgit v1.2.3 From f2eaae197f4590c4d96f31b09b0ee9067421a95c Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Mon, 18 Sep 2006 16:22:34 -0400 Subject: Driver core: Fix potential deadlock in driver core There is a potential deadlock in the driver core. It boils down to the fact that bus_remove_device() calls klist_remove() instead of klist_del(), thereby waiting until the reference count of the klist_node in the bus's klist of devices drops to 0. The refcount can't reach 0 so long as a modprobe process is trying to bind a new driver to the device being removed, by calling __driver_attach(). The problem is that __driver_attach() tries to acquire the device's parent's semaphore, but the caller of bus_remove_device() is quite likely to own that semaphore already. It isn't sufficient just to replace klist_remove() with klist_del(). Doing so runs the risk that the device would remain on the bus's klist of devices for some time, and so could be bound to another driver even after it was unregistered. What's needed is a new way to distinguish whether or not a device is registered, based on a criterion other than whether its klist_node is linked into the bus's klist of devices. That way driver binding can fail when the device is unregistered, even if it is still linked into the klist. This patch (as782) implements the solution, by adding a new bitflag to indiate when a struct device is registered, by testing the flag before allowing a driver to bind a device, and by changing the definition of the device_is_registered() inline. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- include/linux/device.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index 74246efba931..662e6a10144e 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -329,6 +329,7 @@ struct device { struct kobject kobj; char bus_id[BUS_ID_SIZE]; /* position on parent bus */ + unsigned is_registered:1; struct device_attribute uevent_attr; struct device_attribute *devt_attr; @@ -381,7 +382,7 @@ dev_set_drvdata (struct device *dev, void *data) static inline int device_is_registered(struct device *dev) { - return klist_node_attached(&dev->knode_bus); + return dev->is_registered; } /* -- cgit v1.2.3