The following commit has been merged in the linux branch: commit 1a6f2a7512021ceae3c4201c7aab07f032e9ce91 Author: Dmitry Torokhov dmitry.torokhov@gmail.com Date: Mon Oct 12 20:17:41 2009 -0700

Driver core: allow certain drivers prohibit bind/unbind via sysfs

Platform drivers registered via platform_driver_probe() can be bound to devices only once, upon registration, because discard their probe() routines to save memory. Unbinding the driver through sysfs 'unbind' leaves the device stranded and confuses users so let's not create bind and unbind attributes for such drivers.

Signed-off-by: Dmitry Torokhov dtor@mail.ru Cc: Éric Piel eric.piel@tremplin-utc.net Signed-off-by: Greg Kroah-Hartman gregkh@suse.de

diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 973bf2a..63c143e 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -689,15 +689,19 @@ int bus_add_driver(struct device_driver *drv) printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n", __func__, drv->name); } - error = add_bind_files(drv); - if (error) { - /* Ditto */ - printk(KERN_ERR "%s: add_bind_files(%s) failed\n", - __func__, drv->name); + + if (!drv->suppress_bind_attrs) { + error = add_bind_files(drv); + if (error) { + /* Ditto */ + printk(KERN_ERR "%s: add_bind_files(%s) failed\n", + __func__, drv->name); + } }

kobject_uevent(&priv->kobj, KOBJ_ADD); return 0; + out_unregister: kfree(drv->p); drv->p = NULL; @@ -720,7 +724,8 @@ void bus_remove_driver(struct device_driver *drv) if (!drv->bus) return;

- remove_bind_files(drv); + if (!drv->suppress_bind_attrs) + remove_bind_files(drv); driver_remove_attrs(drv->bus, drv); driver_remove_file(drv, &driver_attr_uevent); klist_remove(&drv->p->knode_bus); diff --git a/drivers/base/platform.c b/drivers/base/platform.c index ed156a1..4fa954b 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -521,11 +521,15 @@ int __init_or_module platform_driver_probe(struct platform_driver *drv, { int retval, code;

+ /* make sure driver won't have bind/unbind attributes */ + drv->driver.suppress_bind_attrs = true; + /* temporary section violation during probe() */ drv->probe = probe; retval = code = platform_driver_register(drv);

- /* Fixup that section violation, being paranoid about code scanning + /* + * Fixup that section violation, being paranoid about code scanning * the list of drivers in order to probe new devices. Check to see * if the probe was successful, and make sure any forced probes of * new devices fail. diff --git a/include/linux/device.h b/include/linux/device.h index aca31bf..2ea3e49 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -124,7 +124,9 @@ struct device_driver { struct bus_type *bus;

struct module *owner; - const char *mod_name; /* used for built-in modules */ + const char *mod_name; /* used for built-in modules */ + + bool suppress_bind_attrs; /* disables bind/unbind via sysfs */

int (*probe) (struct device *dev); int (*remove) (struct device *dev);