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path: root/drivers/base/bus.c
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* CONFIG_SYSFS_DEPRECATED - bus symlinksKay Sievers2006-12-01
| | | | | | | | Turn off the bus symlinks if CONFIG_SYSFS_DEPRECATED is enabled Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Driver core: add notification of bus eventsBenjamin Herrenschmidt2006-12-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I finally did as you suggested and added the notifier to the struct bus_type itself. There are still problems to be expected is something attaches to a bus type where the code can hook in different struct device sub-classes (which is imho a big bogosity but I won't even try to argue that case now) but it will solve nicely a number of issues I've had so far. That also means that clients interested in registering for such notifications have to do it before devices are added and after bus types are registered. Fortunately, most bus types that matter for the various usage scenarios I have in mind are registerd at postcore_initcall time, which means I have a really nice spot at arch_initcall time to add my notifiers. There are 4 notifications provided. Device being added (before hooked to the bus) and removed (failure of previous case or after being unhooked from the bus), along with driver being bound to a device and about to be unbound. The usage I have for these are: - The 2 first ones are used to maintain a struct device_ext that is hooked to struct device.firmware_data. This structure contains for now a pointer to the Open Firmware node related to the device (if any), the NUMA node ID (for quick access to it) and the DMA operations pointers & iommu table instance for DMA to/from this device. For bus types I own (like IBM VIO or EBUS), I just maintain that structure directly from the bus code when creating the devices. But for bus types managed by generic code like PCI or platform (actually, of_platform which is a variation of platform linked to Open Firmware device-tree), I need this notifier. - The other two ones have a completely different usage scenario. I have cases where multiple devices and their drivers depend on each other. For example, the IBM EMAC network driver needs to attach to a MAL DMA engine which is a separate device, and a PHY interface which is also a separate device. They are all of_platform_device's (well, about to be with my upcoming patches) but there is no say in what precise order the core will "probe" them and instanciate the various modules. The solution I found for that is to have the drivers for emac to use multithread_probe, and wait for a driver to be bound to the target MAL and PHY control devices (the device-tree contains reference to the MAL and PHY interface nodes, which I can then match to of_platform_devices). Right now, I've been polling, but with that notifier, I can more cleanly wait (with a timeout of course). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Driver core: bus: remove indentation levelJeff Garzik2006-10-18
| | | | | | | | | | | | Before potentially fixing up these functions, this cosmetic change reduces the indentation level to make the code easier to read and maintain. No functional changes at all. Signed-off-by: Jeff Garzik <jeff@garzik.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Driver core: Don't ignore error returns from probingAlan Stern2006-10-18
| | | | | | | | | | | | | This patch (as797) fixes device_add() in the driver core. It needs to pay attention when the driver for a new device reports an error. At the same time, since bus_remove_device() undoes the effects of both bus_add_device() and bus_attach_device(), it needs to check whether the bus_attach_device step failed. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* driver core fixes: bus_add_device() cleanup on errorCornelia Huck2006-10-18
| | | | | | | | | Correct cleanup in the error path of bus_add_device(). Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* driver core fixes: bus_add_attrs() retval checkCornelia Huck2006-10-18
| | | | | | | | | Check return value of bus_add_attrs() in bus_register(). Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Driver core: Remove unneeded routines from driver coreAlan Stern2006-09-26
| | | | | | | | | | | | | | | | | | | | This patch (as783) simplifies the driver core slightly by removing four unnecessary _get and _put methods. It is vital that when a driver is removed from its bus's klist of registered drivers, or when a device is removed from a driver's klist of bound devices, that the klist updates complete synchronously. Otherwise the kernel might try binding an unregistered driver to a newly-registered device, or adding a device to the klist for a new driver before it has been removed from the old driver's klist. Since the removals must be synchronous, they don't need to update any reference counts. Hence the _get and _put methods can be dispensed with. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Driver core: Fix potential deadlock in driver coreAlan Stern2006-09-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* drivers/base: check errorsAndrew Morton2006-09-26
| | | | | | | | | | | Add lots of return-value checking. <pcornelia.huck@de.ibm.com>: fix bus_rescan_devices()] Cc: "Randy.Dunlap" <rdunlap@xenotime.net> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Driver core: fixed add_bind_files() definitionYoichi Yuasa2006-09-26
| | | | | | | | | When CONFIG_HOTPLUG is n, add_bind_files() definition is wrong. This patch has fixed it. Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] Driver core: bus.c cleanupsAdrian Bunk2006-07-12
| | | | | | | | | This patch contains the following cleanups: - make the needlessly global bus_subsys static - #if 0 the unused find_bus() Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Remove obsolete #include <linux/config.h>Jörn Engel2006-06-30
| | | | | Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* [PATCH] Driver core: add generic "subsystem" link to all devicesKay Sievers2006-06-21
| | | | | | | | | | | Like the SUBSYTEM= key we find in the environment of the uevent, this creates a generic "subsystem" link in sysfs for every device. Userspace usually doesn't care at all if its a "class" or a "bus" device. This provides an unified way to determine the subsytem of a device, regardless of the way the driver core has created it. Signed-off-by: Kay Sievers <kay.sievers@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] Driver Core: remove unused exportsGreg Kroah-Hartman2006-06-21
| | | | | Cc: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] Driver core: bus device event delayKay Sievers2006-06-21
| | | | | | | split bus_add_device() and send device uevents after sysfs population Signed-off-by: Kay Sievers <kay.sievers@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] driver core: driver_bind attribute returns incorrect valueRyan Wilson2006-04-14
| | | | | | | | | | | | | | | | | | | | | The manual driver <-> device binding attribute in sysfs doesn't return the correct value on failure or success of driver_probe_device. driver_probe_device returns 1 on success (the driver accepted the device) or 0 on probe failure (when the driver didn't accept the device but no real error occured). However, the attribute can't just return 0 or 1, it must return the number of bytes consumed from buf or an error value. Returning 0 indicates to userspace that nothing was written (even though the kernel has tried to do the bind/probe and failed). Returning 1 indicates that only one character was accepted in which case userspace will re-try the write with a partial string. A more correct version of driver_bind would return count (to indicate the entire string was consumed) when driver_probe_device returns 1 and -ENODEV when driver_probe_device returns 0. This patch makes that change. Signed-off-by: Ryan Wilson <hap9@epoch.ncsc.mil> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [SCSI] drivers/base/bus.c - export reprobeMoore, Eric2006-03-14
| | | | | | | | | | | | | | Adding support for exposing hidden raid components for sg interface. The sdev->no_uld_attach flag will set set accordingly. The sas module supports adding/removing raid volumes using online storage management application interface. This patch was provided to me by Christoph Hellwig. Signed-off-by: Eric Moore <Eric.Moore@lsil.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
* [PATCH] drivers/base/bus.c warning fixesRussell King2006-02-07
| | | | | | | | | | | | | drivers/base/bus.c:166: warning: `driver_attr_unbind' defined but not used drivers/base/bus.c:194: warning: `driver_attr_bind' defined but not used Looks like these two attributes and supporting functions want to be #ifdef HOTPLUG'd Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Driver core: only all userspace bind/unbind if CONFIG_HOTPLUG is enabledGreg Kroah-Hartman2006-01-04
| | | | | | | | | Thanks to drivers making their id tables __devinit, we can't allow userspace to bind or unbind drivers from devices manually through sysfs. So we only allow this if CONFIG_HOTPLUG is enabled. Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] Hold the device's parent's lock during probe and removeAlan Stern2006-01-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch (as604) makes the driver core hold a device's parent's lock as well as the device's lock during calls to the probe and remove methods in a driver. This facility is needed by USB device drivers, owing to the peculiar way USB devices work: A device provides multiple interfaces, and drivers are bound to interfaces rather than to devices; Nevertheless a reset, reset-configuration, suspend, or resume affects the entire device and requires the caller to hold the lock for the device, not just a lock for one of the interfaces. Since a USB driver's probe method is always called with the interface lock held, the locking order rules (always lock parent before child) prevent these methods from acquiring the device lock. The solution provided here is to call all probe and remove methods, for all devices (not just USB), with the parent lock already acquired. Although currently only the USB subsystem requires these changes, people have mentioned in prior discussion that the overhead of acquiring an extra semaphore in all the prove/remove sequences is not overly large. Up to now, the USB core has been using its own set of private semaphores. A followup patch will remove them, relying entirely on the device semaphores provided by the driver core. The code paths affected by this patch are: device_add and device_del: The USB core already holds the parent lock, so no actual change is needed. driver_register and driver_unregister: The driver core will now lock both the parent and the device before probing or removing. driver_bind and driver_unbind (in sysfs): These routines will now lock both the parent and the device before binding or unbinding. bus_rescan_devices: The helper routine will lock the parent before probing a device. I have not tested this patch for conflicts with other subsystems. As far as I can see, the only possibility of conflict would lie in the bus_rescan_devices pathway, and it seems pretty remote. Nevertheless, it would be good for this to get a lot of testing in -mm. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] Small fixes to driver coreAlan Stern2005-11-24
| | | | | | | | | | | | | | | This patch (as603) makes a few small fixes to the driver core: Change spin_lock_irq for a klist lock to spin_lock; Fix reference count leaks; Minor spelling and formatting changes. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by Patrick Mochel <mochel@digitalimplant.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fix klist semantics for lists which have elements removed on traversalJames Bottomley2005-09-07
| | | | | | | | | | | | | | | | | | | | | The problem is that klists claim to provide semantics for safe traversal of lists which are being modified. The failure case is when traversal of a list causes element removal (a fairly common case). The issue is that although the list node is refcounted, if it is embedded in an object (which is universally the case), then the object will be freed regardless of the klist refcount leading to slab corruption because the klist iterator refers to the prior element to get the next. The solution is to make the klist take and release references to the embedding object meaning that the embedding object won't be released until the list relinquishes the reference to it. (akpm: fast-track this because it's needed for the 2.6.13 scsi merge) Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] klist: fix klist to have the same klist_add semantics as list_headJames Bottomley2005-09-05
| | | | | | | | | | | | | | | | | | at the moment, the list_head semantics are list_add(node, head) whereas current klist semantics are klist_add(head, node) This is bound to cause confusion, and since klist is the newcomer, it should follow the list_head semantics. I also added missing include guards to klist.h Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] Fix manual binding infinite loopGreg Kroah-Hartman2005-09-05
| | | | | | | | | | | Fix for manual binding of drivers to devices. Problem is if you pass in a valid device id, but the driver refuses to bind. Infinite loop as write() tries to resubmit the data it just sent. Thanks to Michal Ostrowski <mostrows@watson.ibm.com> for pointing the problem out. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] Fix manual binding infinite loopGreg KH2005-08-18
| | | | | | | | | | | | Fix for manual binding of drivers to devices. Problem is if you pass in a valid device id, but the driver refuses to bind. Infinite loop as write() tries to resubmit the data it just sent. Thanks to Michal Ostrowski <mostrows@watson.ibm.com> for pointing the problem out. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] driver core: change bus_rescan_devices to return voidGreg Kroah-Hartman2005-06-30
| | | | | | | | No one was looking at the return value of bus_rescan_devices, and it really wasn't anything that anyone in the kernel would ever care about. So change it which enabled some counting code to be removed also. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] driver core: Add the ability to bind drivers to devices from userspaceGreg Kroah-Hartman2005-06-30
| | | | | | | | | | | | | | | This adds a single file, "bind", to the sysfs directory of every driver registered with the driver core. To bind a device to a driver, write the bus id of the device you wish to bind to that specific driver to the "bind" file (remember to not add a trailing \n). If that bus id matches a device on that bus, and it does not currently have a driver bound to it, the probe sequence will be initiated with that driver and device. Note, this requires that the driver itself be willing and able to accept that device (usually through a device id type table). This patch does not make it possible to override the driver's id table. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] driver core: Add the ability to unbind drivers to devices from userspaceGreg Kroah-Hartman2005-06-30
| | | | | | | | | This adds a single file, "unbind", to the sysfs directory of every device that is currently bound to a driver. To unbind the driver from the device, write anything to this file and they will be disconnected from each other. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] driver core: add bus_find_device & driver_find_device functionsCornelia Huck2005-06-30
| | | | | | | | Add bus_find_device() and driver_find_device() which allow searching for a device in the bus's resp. the driver's klist and obtain a reference on it. Signed-off-by: Cornelia Huck <cohuck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] driver core: Fix up the device_attach() error handling in ↵Greg Kroah-Hartman2005-06-23
| | | | | | | | | | bus_add_device() Don't error out if something "bad" happens when trying to bind a driver to a device. We want the sysfs attributes to be present for later when we try to tear down the device. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] driver core: fix error handling in bus_add_deviceHannes Reinecke2005-06-20
| | | | | | | | | The error handling in bus_add_device() and device_attach() is simply non-existing. This patch propagates any error from device_attach to the upper layers to allow for a proper recovery. From: Hannes Reinecke <hare@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] Fix up bus code and remove use of rwsem.mochel@digitalimplant.org2005-06-20
| | | | | | | | | - Don't add devices to bus's embedded kset, since it's not used by anyone anymore. - Don't need to take the bus rwsem when calling {device,driver}_attach(), since those functions use the klists and the klists' spinlocks. Signed-off-by: Patrick Mochel <mochel@digitalimplant.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] Add a klist to struct bus_type for its drivers.mochel@digitalimplant.org2005-06-20
| | | | | | | | - Use it in bus_for_each_drv(). - Use the klist spinlock instead of the bus rwsem. Signed-off-by: Patrick Mochel <mochel@digitalimplant.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] Add a klist to struct bus_type for its devices.mochel@digitalimplant.org2005-06-20
| | | | | | | | - Use it for bus_for_each_dev(). - Use the klist spinlock instead of the bus rwsem. Signed-off-by: Patrick Mochel <mochel@digitalimplant.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] Move device/driver code to drivers/base/dd.cmochel@digitalimplant.org2005-06-20
| | | | | | | | | | This relocates the driver binding/unbinding code to drivers/base/dd.c. This is done for two reasons: One, it's not code related to the bus_type itself; it uses some from that, some from devices, and some from drivers. And Two, it will make it easier to do some of the upcoming lock removal on that code.. Signed-off-by: Patrick Mochel <mochel@digitalimplant.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] Add a semaphore to struct device to synchronize calls to its driver.mochel@digitalimplant.org2005-06-20
| | | | | | | | | | | | 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>
* [PATCH] sysfs: (driver/base) if show/store is missing return -EIODmitry Torokhov2005-06-20
| | | | | | | | | sysfs: fix drivers/base so if an attribute doesn't implement show or store method read/write will return -EIO instead of 0. Signed-off-by: Dmitry Torokhov <dtor@mail.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] Driver Core: remove driver model detach_stateDavid Brownell2005-05-17
| | | | | | | | | | | | | | | | The driver model has a "detach_state" mechanism that: - Has never been used by any in-kernel drive; - Is superfluous, since driver remove() methods can do the same thing; - Became buggy when the suspend() parameter changed semantics and type; - Could self-deadlock when called from certain suspend contexts; - Is effectively wasted documentation, object code, and headspace. This removes that "detach_state" mechanism; net code shrink, as well as a per-device saving in the driver model and sysfs. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] drivers/base/bus.c: fix iteration in driver_detach()Roman Kagan2005-05-05
| | | | | | | | | | | | | | | | | With 2.6.11 and 2.6.12-rc2 (and perhaps a few versions before) usb drivers for multi-interface devices, which do usb_driver_release_interface() in their disconnect(), make rmmod hang. It turns out to be due to a bug in drivers/base/bus.c:driver_detach(), that iterates over the list of attached devices with list_for_each_safe() under an assumption that device_release_driver() only releases the current device, while it may also call device_release_driver() for other devices on the same list. The following patch fixes it. Please consider applying. Signed-off-by: Roman Kagan <rkagan@mail.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Linux-2.6.12-rc2Linus Torvalds2005-04-16
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!