On Mon, Nov 05, 2007 at 11:57:14AM +0100, Peter Zijlstra wrote:
> Hmm, the problem seems to be stuff like:
> 
> add usb driver to pci
>   scan pci devices
>      add usb host controller device
>         scan usb devices
>           add usb hub device
>             scan usb devices
>               add usb .....
> 
> This seems to be able to go on forever, as long as one can cascade usb
> hubs.

USB hubs only work 7 deep, so there is a limit.

> Doesn't seem like an ideal thing to do from a stack space POV either.
> 
> Would it be possible to break at the second scan, that is the device
> probe and stick that into a workqueue or something. Then we'd only ever
> have driver->device nesting.

Alan and Oliver have done some work in this area I think, combined with
the suspend/bind/unbind issues.  I'll let them comment on your patch :)

thanks,

greg k-h

---
 drivers/base/bus.c                |   20 ++++++++++----------
 drivers/base/class.c              |   22 +++++++++++-----------
 drivers/base/core.c               |   20 +++++++++-----------
 drivers/base/dd.c                 |   38 +++++++++++++++++++-------------------
 drivers/base/power/main.c         |    8 ++++----
 drivers/pci/bus.c                 |    4 ++--
 drivers/pnp/interface.c           |   10 +++++-----
 drivers/pnp/manager.c             |   18 +++++++++---------
 drivers/power/power_supply_core.c |    8 ++++----
 drivers/rtc/interface.c           |    4 ++--
 drivers/scsi/hosts.c              |    4 ++--
 drivers/spi/spi.c                 |   10 +++++-----
 drivers/usb/core/hub.c            |    4 ++--
 include/linux/device.h            |   18 +++++++++++-------
 include/linux/usb.h               |    6 +++---
 15 files changed, 98 insertions(+), 96 deletions(-)

Index: linux-2.6-2/drivers/base/bus.c
===================================================================
--- linux-2.6-2.orig/drivers/base/bus.c
+++ linux-2.6-2/drivers/base/bus.c
@@ -190,10 +190,10 @@ static ssize_t driver_unbind(struct devi
        dev = bus_find_device(bus, NULL, (void *)buf, driver_helper);
        if (dev && dev->driver == drv) {
                if (dev->parent)        /* Needed for USB */
-                       down(&dev->parent->sem);
+                       mutex_lock_nested(&dev->parent->mutex, DRIVER_PARENT);
                device_release_driver(dev);
                if (dev->parent)
-                       up(&dev->parent->sem);
+                       mutex_unlock(&dev->parent->mutex);
                err = count;
        }
        put_device(dev);
@@ -217,12 +217,12 @@ static ssize_t driver_bind(struct device
        dev = bus_find_device(bus, NULL, (void *)buf, driver_helper);
        if (dev && dev->driver == NULL) {
                if (dev->parent)        /* Needed for USB */
-                       down(&dev->parent->sem);
-               down(&dev->sem);
+                       mutex_lock_nested(&dev->parent->mutex, DRIVER_PARENT);
+               mutex_lock_nested(&dev->mutex, DRIVER_NORMAL);
                err = driver_probe_device(drv, dev);
-               up(&dev->sem);
+               mutex_unlock(&dev->mutex);
                if (dev->parent)
-                       up(&dev->parent->sem);
+                       mutex_unlock(&dev->parent->mutex);
 
                if (err > 0)            /* success */
                        err = count;
@@ -711,10 +711,10 @@ static int __must_check bus_rescan_devic
 
        if (!dev->driver) {
                if (dev->parent)        /* Needed for USB */
-                       down(&dev->parent->sem);
+                       mutex_lock_nested(&dev->parent->mutex, DEVICE_PARENT);
                ret = device_attach(dev);
                if (dev->parent)
-                       up(&dev->parent->sem);
+                       mutex_unlock(&dev->parent->mutex);
        }
        return ret < 0 ? ret : 0;
 }
@@ -745,10 +745,10 @@ int device_reprobe(struct device *dev)
 {
        if (dev->driver) {
                if (dev->parent)        /* Needed for USB */
-                       down(&dev->parent->sem);
+                       mutex_lock_nested(&dev->parent->mutex, DEVICE_PARENT);
                device_release_driver(dev);
                if (dev->parent)
-                       up(&dev->parent->sem);
+                       mutex_unlock(&dev->parent->mutex);
        }
        return bus_rescan_devices_helper(dev, NULL);
 }
Index: linux-2.6-2/drivers/base/class.c
===================================================================
--- linux-2.6-2.orig/drivers/base/class.c
+++ linux-2.6-2/drivers/base/class.c
@@ -144,7 +144,7 @@ int class_register(struct class * cls)
        INIT_LIST_HEAD(&cls->devices);
        INIT_LIST_HEAD(&cls->interfaces);
        kset_init(&cls->class_dirs);
-       init_MUTEX(&cls->sem);
+       mutex_init(&cls->mutex);
        error = kobject_set_name(&cls->subsys.kobj, "%s", cls->name);
        if (error)
                return error;
@@ -617,13 +617,13 @@ int class_device_add(struct class_device
        kobject_uevent(&class_dev->kobj, KOBJ_ADD);
 
        /* notify any interfaces this device is now here */
-       down(&parent_class->sem);
+       mutex_lock_nested(&parent_class->mutex, SINGLE_DEPTH_NESTING);
        list_add_tail(&class_dev->node, &parent_class->children);
        list_for_each_entry(class_intf, &parent_class->interfaces, node) {
                if (class_intf->add)
                        class_intf->add(class_dev, class_intf);
        }
-       up(&parent_class->sem);
+       mutex_unlock(&parent_class->mutex);
 
        goto out1;
 
@@ -725,12 +725,12 @@ void class_device_del(struct class_devic
        struct class_interface *class_intf;
 
        if (parent_class) {
-               down(&parent_class->sem);
+               mutex_lock_nested(&parent_class->mutex, SINGLE_DEPTH_NESTING);
                list_del_init(&class_dev->node);
                list_for_each_entry(class_intf, &parent_class->interfaces, node)
                        if (class_intf->remove)
                                class_intf->remove(class_dev, class_intf);
-               up(&parent_class->sem);
+               mutex_unlock(&parent_class->mutex);
        }
 
        if (class_dev->dev) {
@@ -772,14 +772,14 @@ void class_device_destroy(struct class *
        struct class_device *class_dev = NULL;
        struct class_device *class_dev_tmp;
 
-       down(&cls->sem);
+       mutex_lock(&cls->mutex);
        list_for_each_entry(class_dev_tmp, &cls->children, node) {
                if (class_dev_tmp->devt == devt) {
                        class_dev = class_dev_tmp;
                        break;
                }
        }
-       up(&cls->sem);
+       mutex_unlock(&cls->mutex);
 
        if (class_dev)
                class_device_unregister(class_dev);
@@ -812,7 +812,7 @@ int class_interface_register(struct clas
        if (!parent)
                return -EINVAL;
 
-       down(&parent->sem);
+       mutex_lock_nested(&parent->mutex, SINGLE_DEPTH_NESTING);
        list_add_tail(&class_intf->node, &parent->interfaces);
        if (class_intf->add) {
                list_for_each_entry(class_dev, &parent->children, node)
@@ -822,7 +822,7 @@ int class_interface_register(struct clas
                list_for_each_entry(dev, &parent->devices, node)
                        class_intf->add_dev(dev, class_intf);
        }
-       up(&parent->sem);
+       mutex_unlock(&parent->mutex);
 
        return 0;
 }
@@ -836,7 +836,7 @@ void class_interface_unregister(struct c
        if (!parent)
                return;
 
-       down(&parent->sem);
+       mutex_lock_nested(&parent->mutex, SINGLE_DEPTH_NESTING);
        list_del_init(&class_intf->node);
        if (class_intf->remove) {
                list_for_each_entry(class_dev, &parent->children, node)
@@ -846,7 +846,7 @@ void class_interface_unregister(struct c
                list_for_each_entry(dev, &parent->devices, node)
                        class_intf->remove_dev(dev, class_intf);
        }
-       up(&parent->sem);
+       mutex_unlock(&parent->mutex);
 
        class_put(parent);
 }
Index: linux-2.6-2/drivers/base/core.c
===================================================================
--- linux-2.6-2.orig/drivers/base/core.c
+++ linux-2.6-2/drivers/base/core.c
@@ -19,8 +19,6 @@
 #include <linux/kdev_t.h>
 #include <linux/notifier.h>
 
-#include <asm/semaphore.h>
-
 #include "base.h"
 #include "power/power.h"
 
@@ -531,7 +529,7 @@ void device_initialize(struct device *de
                   klist_children_put);
        INIT_LIST_HEAD(&dev->dma_pools);
        INIT_LIST_HEAD(&dev->node);
-       init_MUTEX(&dev->sem);
+       mutex_init(&dev->mutex);
        spin_lock_init(&dev->devres_lock);
        INIT_LIST_HEAD(&dev->devres_head);
        device_init_wakeup(dev, 0);
@@ -782,7 +780,7 @@ int device_add(struct device *dev)
                klist_add_tail(&dev->knode_parent, &parent->klist_children);
 
        if (dev->class) {
-               down(&dev->class->sem);
+               mutex_lock(&dev->class->mutex);
                /* tie the class to the device */
                list_add_tail(&dev->node, &dev->class->devices);
 
@@ -790,7 +788,7 @@ int device_add(struct device *dev)
                list_for_each_entry(class_intf, &dev->class->interfaces, node)
                        if (class_intf->add_dev)
                                class_intf->add_dev(dev, class_intf);
-               up(&dev->class->sem);
+               mutex_unlock(&dev->class->mutex);
        }
  Done:
        put_device(dev);
@@ -926,14 +924,14 @@ void device_del(struct device * dev)
                        sysfs_remove_link(&dev->kobj, "device");
                }
 
-               down(&dev->class->sem);
+               mutex_lock(&dev->class->mutex);
                /* notify any interfaces that the device is now gone */
                list_for_each_entry(class_intf, &dev->class->interfaces, node)
                        if (class_intf->remove_dev)
                                class_intf->remove_dev(dev, class_intf);
                /* remove the device from the class list */
                list_del_init(&dev->node);
-               up(&dev->class->sem);
+               mutex_unlock(&dev->class->mutex);
 
                /* If we live in a parent class-directory, unreference it */
                if (dev->kobj.parent->kset == &dev->class->class_dirs) {
@@ -944,7 +942,7 @@ void device_del(struct device * dev)
                         * if we are the last child of our class, delete
                         * our class-directory at this parent
                         */
-                       down(&dev->class->sem);
+                       mutex_lock(&dev->class->mutex);
                        list_for_each_entry(d, &dev->class->devices, node) {
                                if (d == dev)
                                        continue;
@@ -957,7 +955,7 @@ void device_del(struct device * dev)
                                kobject_del(dev->kobj.parent);
 
                        kobject_put(dev->kobj.parent);
-                       up(&dev->class->sem);
+                       mutex_unlock(&dev->class->mutex);
                }
        }
        device_remove_file(dev, &uevent_attr);
@@ -1166,14 +1164,14 @@ void device_destroy(struct class *class,
        struct device *dev = NULL;
        struct device *dev_tmp;
 
-       down(&class->sem);
+       mutex_lock(&class->mutex);
        list_for_each_entry(dev_tmp, &class->devices, node) {
                if (dev_tmp->devt == devt) {
                        dev = dev_tmp;
                        break;
                }
        }
-       up(&class->sem);
+       mutex_unlock(&class->mutex);
 
        if (dev)
                device_unregister(dev);
Index: linux-2.6-2/drivers/base/dd.c
===================================================================
--- linux-2.6-2.orig/drivers/base/dd.c
+++ linux-2.6-2/drivers/base/dd.c
@@ -82,7 +82,7 @@ static void driver_sysfs_remove(struct d
  *     for before calling this. (It is ok to call with no other effort
  *     from a driver's probe() method.)
  *
- *     This function must be called with @dev->sem held.
+ *     This function must be called with @dev->mutex held.
  */
 int device_bind_driver(struct device *dev)
 {
@@ -180,8 +180,8 @@ int driver_probe_done(void)
  * This function returns 1 if a match is found, -ENODEV if the device is
  * not registered, and 0 otherwise.
  *
- * This function must be called with @dev->sem held.  When called for a
- * USB interface, @dev->parent->sem must be held as well.
+ * This function must be called with @dev->mutex held.  When called for a
+ * USB interface, @dev->parent->mutex must be held as well.
  */
 int driver_probe_device(struct device_driver * drv, struct device * dev)
 {
@@ -219,13 +219,13 @@ static int __device_attach(struct device
  *     0 if no matching device was found;
  *     -ENODEV if the device is not registered.
  *
- *     When called for a USB interface, @dev->parent->sem must be held.
+ *     When called for a USB interface, @dev->parent->mutex must be held.
  */
 int device_attach(struct device * dev)
 {
        int ret = 0;
 
-       down(&dev->sem);
+       mutex_lock_nested(&dev->mutex, DEVICE_NORMAL);
        if (dev->driver) {
                ret = device_bind_driver(dev);
                if (ret == 0)
@@ -237,7 +237,7 @@ int device_attach(struct device * dev)
        } else {
                ret = bus_for_each_drv(dev->bus, NULL, dev, __device_attach);
        }
-       up(&dev->sem);
+       mutex_unlock(&dev->mutex);
        return ret;
 }
 
@@ -256,13 +256,13 @@ static int __driver_attach(struct device
         */
 
        if (dev->parent)        /* Needed for USB */
-               down(&dev->parent->sem);
-       down(&dev->sem);
+               mutex_lock_nested(&dev->parent->mutex, DRIVER_PARENT);
+       mutex_lock_nested(&dev->mutex, DRIVER_NORMAL);
        if (!dev->driver)
                driver_probe_device(drv, dev);
-       up(&dev->sem);
+       mutex_unlock(&dev->mutex);
        if (dev->parent)
-               up(&dev->parent->sem);
+               mutex_unlock(&dev->parent->mutex);
 
        return 0;
 }
@@ -282,8 +282,8 @@ int driver_attach(struct device_driver *
 }
 
 /*
- *     __device_release_driver() must be called with @dev->sem held.
- *     When called for a USB interface, @dev->parent->sem must be held as well.
+ *     __device_release_driver() must be called with @dev->mutex held.
+ *     When called for a USB interface, @dev->parent->mutex must be held as 
well.
  */
 static void __device_release_driver(struct device * dev)
 {
@@ -315,7 +315,7 @@ static void __device_release_driver(stru
  *     @dev:   device.
  *
  *     Manually detach device from driver.
- *     When called for a USB interface, @dev->parent->sem must be held.
+ *     When called for a USB interface, @dev->parent->mutex must be held.
  */
 void device_release_driver(struct device * dev)
 {
@@ -324,9 +324,9 @@ void device_release_driver(struct device
         * within their ->remove callback for the same device, they
         * will deadlock right here.
         */
-       down(&dev->sem);
+       mutex_lock_nested(&dev->mutex, DEVICE_NORMAL);
        __device_release_driver(dev);
-       up(&dev->sem);
+       mutex_unlock(&dev->mutex);
 }
 
 
@@ -350,13 +350,13 @@ void driver_detach(struct device_driver 
                spin_unlock(&drv->klist_devices.k_lock);
 
                if (dev->parent)        /* Needed for USB */
-                       down(&dev->parent->sem);
-               down(&dev->sem);
+                       mutex_lock_nested(&dev->parent->mutex, DRIVER_PARENT);
+               mutex_lock_nested(&dev->mutex, DRIVER_NORMAL);
                if (dev->driver == drv)
                        __device_release_driver(dev);
-               up(&dev->sem);
+               mutex_unlock(&dev->mutex);
                if (dev->parent)
-                       up(&dev->parent->sem);
+                       mutex_unlock(&dev->parent->mutex);
                put_device(dev);
        }
 }
Index: linux-2.6-2/drivers/base/power/main.c
===================================================================
--- linux-2.6-2.orig/drivers/base/power/main.c
+++ linux-2.6-2/drivers/base/power/main.c
@@ -81,7 +81,7 @@ static int resume_device(struct device *
        TRACE_DEVICE(dev);
        TRACE_RESUME(0);
 
-       down(&dev->sem);
+       mutex_lock(&dev->mutex);
 
        if (dev->bus && dev->bus->resume) {
                dev_dbg(dev,"resuming\n");
@@ -98,7 +98,7 @@ static int resume_device(struct device *
                error = dev->class->resume(dev);
        }
 
-       up(&dev->sem);
+       mutex_unlock(&dev->mutex);
 
        TRACE_RESUME(error);
        return error;
@@ -247,7 +247,7 @@ static int suspend_device(struct device 
 {
        int error = 0;
 
-       down(&dev->sem);
+       mutex_lock(&dev->mutex);
        if (dev->power.power_state.event) {
                dev_dbg(dev, "PM: suspend %d-->%d\n",
                        dev->power.power_state.event, state.event);
@@ -270,7 +270,7 @@ static int suspend_device(struct device 
                error = dev->bus->suspend(dev, state);
                suspend_report_result(dev->bus->suspend, error);
        }
-       up(&dev->sem);
+       mutex_unlock(&dev->mutex);
        return error;
 }
 
Index: linux-2.6-2/drivers/pci/bus.c
===================================================================
--- linux-2.6-2.orig/drivers/pci/bus.c
+++ linux-2.6-2/drivers/pci/bus.c
@@ -198,9 +198,9 @@ void pci_walk_bus(struct pci_bus *top, v
                        next = dev->bus_list.next;
 
                /* Run device routines with the device locked */
-               down(&dev->dev.sem);
+               mutex_lock(&dev->dev.mutex);
                cb(dev, userdata);
-               up(&dev->dev.sem);
+               mutex_unlock(&dev->dev.mutex);
        }
        up_read(&pci_bus_sem);
 }
Index: linux-2.6-2/drivers/pnp/interface.c
===================================================================
--- linux-2.6-2.orig/drivers/pnp/interface.c
+++ linux-2.6-2/drivers/pnp/interface.c
@@ -315,7 +315,7 @@ static ssize_t pnp_show_current_resource
        return ret;
 }
 
-extern struct semaphore pnp_res_mutex;
+extern struct mutex pnp_res_mutex;
 
 static ssize_t
 pnp_set_current_resources(struct device *dmdev, struct device_attribute *attr,
@@ -361,10 +361,10 @@ pnp_set_current_resources(struct device 
                goto done;
        }
        if (!strnicmp(buf, "get", 3)) {
-               down(&pnp_res_mutex);
+               mutex_lock(&pnp_res_mutex);
                if (pnp_can_read(dev))
                        dev->protocol->get(dev, &dev->res);
-               up(&pnp_res_mutex);
+               mutex_unlock(&pnp_res_mutex);
                goto done;
        }
        if (!strnicmp(buf, "set", 3)) {
@@ -373,7 +373,7 @@ pnp_set_current_resources(struct device 
                        goto done;
                buf += 3;
                pnp_init_resource_table(&dev->res);
-               down(&pnp_res_mutex);
+               mutex_lock(&pnp_res_mutex);
                while (1) {
                        while (isspace(*buf))
                                ++buf;
@@ -455,7 +455,7 @@ pnp_set_current_resources(struct device 
                        }
                        break;
                }
-               up(&pnp_res_mutex);
+               mutex_unlock(&pnp_res_mutex);
                goto done;
        }
 
Index: linux-2.6-2/drivers/pnp/manager.c
===================================================================
--- linux-2.6-2.orig/drivers/pnp/manager.c
+++ linux-2.6-2/drivers/pnp/manager.c
@@ -14,7 +14,7 @@
 #include <linux/bitmap.h>
 #include "base.h"
 
-DECLARE_MUTEX(pnp_res_mutex);
+DEFINE_MUTEX(pnp_res_mutex);
 
 static int pnp_assign_port(struct pnp_dev *dev, struct pnp_port *rule, int idx)
 {
@@ -297,7 +297,7 @@ static int pnp_assign_resources(struct p
        if (!pnp_can_configure(dev))
                return -ENODEV;
 
-       down(&pnp_res_mutex);
+       mutex_lock(&pnp_res_mutex);
        pnp_clean_resource_table(&dev->res);    /* start with a fresh slate */
        if (dev->independent) {
                port = dev->independent->port;
@@ -366,12 +366,12 @@ static int pnp_assign_resources(struct p
        } else if (dev->dependent)
                goto fail;
 
-       up(&pnp_res_mutex);
+       mutex_unlock(&pnp_res_mutex);
        return 1;
 
 fail:
        pnp_clean_resource_table(&dev->res);
-       up(&pnp_res_mutex);
+       mutex_unlock(&pnp_res_mutex);
        return 0;
 }
 
@@ -396,7 +396,7 @@ int pnp_manual_config_dev(struct pnp_dev
                return -ENOMEM;
        *bak = dev->res;
 
-       down(&pnp_res_mutex);
+       mutex_lock(&pnp_res_mutex);
        dev->res = *res;
        if (!(mode & PNP_CONFIG_FORCE)) {
                for (i = 0; i < PNP_MAX_PORT; i++) {
@@ -416,14 +416,14 @@ int pnp_manual_config_dev(struct pnp_dev
                                goto fail;
                }
        }
-       up(&pnp_res_mutex);
+       mutex_unlock(&pnp_res_mutex);
 
        kfree(bak);
        return 0;
 
 fail:
        dev->res = *bak;
-       up(&pnp_res_mutex);
+       mutex_unlock(&pnp_res_mutex);
        kfree(bak);
        return -EINVAL;
 }
@@ -547,9 +547,9 @@ int pnp_disable_dev(struct pnp_dev *dev)
        dev->active = 0;
 
        /* release the resources so that other devices can use them */
-       down(&pnp_res_mutex);
+       mutex_lock(&pnp_res_mutex);
        pnp_clean_resource_table(&dev->res);
-       up(&pnp_res_mutex);
+       mutex_unlock(&pnp_res_mutex);
 
        return 1;
 }
Index: linux-2.6-2/drivers/power/power_supply_core.c
===================================================================
--- linux-2.6-2.orig/drivers/power/power_supply_core.c
+++ linux-2.6-2/drivers/power/power_supply_core.c
@@ -31,7 +31,7 @@ static void power_supply_changed_work(st
        for (i = 0; i < psy->num_supplicants; i++) {
                struct device *dev;
 
-               down(&power_supply_class->sem);
+               mutex_lock(&power_supply_class->mutex);
                list_for_each_entry(dev, &power_supply_class->devices, node) {
                        struct power_supply *pst = dev_get_drvdata(dev);
 
@@ -40,7 +40,7 @@ static void power_supply_changed_work(st
                                        pst->external_power_changed(pst);
                        }
                }
-               up(&power_supply_class->sem);
+               mutex_unlock(&power_supply_class->mutex);
        }
 
        power_supply_update_leds(psy);
@@ -60,7 +60,7 @@ int power_supply_am_i_supplied(struct po
        union power_supply_propval ret = {0,};
        struct device *dev;
 
-       down(&power_supply_class->sem);
+       mutex_lock(&power_supply_class->mutex);
        list_for_each_entry(dev, &power_supply_class->devices, node) {
                struct power_supply *epsy = dev_get_drvdata(dev);
                int i;
@@ -76,7 +76,7 @@ int power_supply_am_i_supplied(struct po
                }
        }
 out:
-       up(&power_supply_class->sem);
+       mutex_unlock(&power_supply_class->mutex);
 
        dev_dbg(psy->dev, "%s %d\n", __FUNCTION__, ret.intval);
 
Index: linux-2.6-2/drivers/rtc/interface.c
===================================================================
--- linux-2.6-2.orig/drivers/rtc/interface.c
+++ linux-2.6-2/drivers/rtc/interface.c
@@ -256,7 +256,7 @@ struct rtc_device *rtc_class_open(char *
        struct device *dev;
        struct rtc_device *rtc = NULL;
 
-       down(&rtc_class->sem);
+       mutex_lock(&rtc_class->mutex);
        list_for_each_entry(dev, &rtc_class->devices, node) {
                if (strncmp(dev->bus_id, name, BUS_ID_SIZE) == 0) {
                        dev = get_device(dev);
@@ -272,7 +272,7 @@ struct rtc_device *rtc_class_open(char *
                        rtc = NULL;
                }
        }
-       up(&rtc_class->sem);
+       mutex_unlock(&rtc_class->mutex);
 
        return rtc;
 }
Index: linux-2.6-2/drivers/scsi/hosts.c
===================================================================
--- linux-2.6-2.orig/drivers/scsi/hosts.c
+++ linux-2.6-2/drivers/scsi/hosts.c
@@ -443,7 +443,7 @@ struct Scsi_Host *scsi_host_lookup(unsig
        struct class_device *cdev;
        struct Scsi_Host *shost = ERR_PTR(-ENXIO), *p;
 
-       down(&class->sem);
+       mutex_lock(&class->mutex);
        list_for_each_entry(cdev, &class->children, node) {
                p = class_to_shost(cdev);
                if (p->host_no == hostnum) {
@@ -451,7 +451,7 @@ struct Scsi_Host *scsi_host_lookup(unsig
                        break;
                }
        }
-       up(&class->sem);
+       mutex_unlock(&class->mutex);
 
        return shost;
 }
Index: linux-2.6-2/drivers/spi/spi.c
===================================================================
--- linux-2.6-2.orig/drivers/spi/spi.c
+++ linux-2.6-2/drivers/spi/spi.c
@@ -499,7 +499,7 @@ struct spi_master *spi_busnum_to_master(
        struct spi_master       *master = NULL;
        struct spi_master       *m;
 
-       down(&spi_master_class.sem);
+       mutex_lock(&spi_master_class.mutex);
        list_for_each_entry(dev, &spi_master_class.children, node) {
                m = container_of(dev, struct spi_master, dev);
                if (m->bus_num == bus_num) {
@@ -507,7 +507,7 @@ struct spi_master *spi_busnum_to_master(
                        break;
                }
        }
-       up(&spi_master_class.sem);
+       mutex_unlock(&spi_master_class.mutex);
        return master;
 }
 EXPORT_SYMBOL_GPL(spi_busnum_to_master);
@@ -587,7 +587,7 @@ int spi_write_then_read(struct spi_devic
                const u8 *txbuf, unsigned n_tx,
                u8 *rxbuf, unsigned n_rx)
 {
-       static DECLARE_MUTEX(lock);
+       static DEFINE_MUTEX(lock);
 
        int                     status;
        struct spi_message      message;
@@ -613,7 +613,7 @@ int spi_write_then_read(struct spi_devic
        }
 
        /* ... unless someone else is using the pre-allocated buffer */
-       if (down_trylock(&lock)) {
+       if (mutex_trylock(&lock)) {
                local_buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
                if (!local_buf)
                        return -ENOMEM;
@@ -632,7 +632,7 @@ int spi_write_then_read(struct spi_devic
        }
 
        if (x[0].tx_buf == buf)
-               up(&lock);
+               mutex_unlock(&lock);
        else
                kfree(local_buf);
 
Index: linux-2.6-2/drivers/usb/core/hub.c
===================================================================
--- linux-2.6-2.orig/drivers/usb/core/hub.c
+++ linux-2.6-2/drivers/usb/core/hub.c
@@ -3143,7 +3143,7 @@ int usb_reset_composite_device(struct us
                for (i = 0; i < config->desc.bNumInterfaces; ++i) {
                        cintf = config->interface[i];
                        if (cintf != iface)
-                               down(&cintf->dev.sem);
+                               mutex_lock(&cintf->dev.mutex);
                        if (device_is_registered(&cintf->dev) &&
                                        cintf->dev.driver) {
                                drv = to_usb_driver(cintf->dev.driver);
@@ -3171,7 +3171,7 @@ int usb_reset_composite_device(struct us
        /* FIXME: Unbind if post_reset returns an error or isn't defined */
                        }
                        if (cintf != iface)
-                               up(&cintf->dev.sem);
+                               mutex_unlock(&cintf->dev.mutex);
                }
        }
 
Index: linux-2.6-2/include/linux/device.h
===================================================================
--- linux-2.6-2.orig/include/linux/device.h
+++ linux-2.6-2/include/linux/device.h
@@ -20,7 +20,7 @@
 #include <linux/types.h>
 #include <linux/module.h>
 #include <linux/pm.h>
-#include <asm/semaphore.h>
+#include <asm/mutex.h>
 #include <asm/atomic.h>
 #include <asm/device.h>
 
@@ -110,7 +110,7 @@ extern int bus_unregister_notifier(struc
 
 /* All 4 notifers below get called with the target struct device *
  * as an argument. Note that those functions are likely to be called
- * with the device semaphore held in the core, so be careful.
+ * with the device mutex held in the core, so be careful.
  */
 #define BUS_NOTIFY_ADD_DEVICE          0x00000001 /* device added */
 #define BUS_NOTIFY_DEL_DEVICE          0x00000002 /* device removed */
@@ -137,7 +137,6 @@ struct device_driver {
        int     (*resume)       (struct device * dev);
 };
 
-
 extern int __must_check driver_register(struct device_driver * drv);
 extern void driver_unregister(struct device_driver * drv);
 
@@ -180,7 +179,7 @@ struct class {
        struct list_head        devices;
        struct list_head        interfaces;
        struct kset             class_dirs;
-       struct semaphore        sem;    /* locks both the children and 
interfaces lists */
+       struct mutex            mutex;  /* locks both the children and 
interfaces lists */
 
        struct class_attribute          * class_attrs;
        struct class_device_attribute   * class_dev_attrs;
@@ -410,9 +409,7 @@ struct device {
        unsigned                is_registered:1;
        unsigned                uevent_suppress:1;
 
-       struct semaphore        sem;    /* semaphore to synchronize calls to
-                                        * its driver.
-                                        */
+       struct mutex            mutex;  /* synchronize calls to its driver. */
 
        struct bus_type * bus;          /* type of bus device is on */
        struct device_driver *driver;   /* which driver has allocated this
@@ -451,6 +448,13 @@ struct device {
        void    (*release)(struct device * dev);
 };
 
+enum {
+       DEVICE_NORMAL,
+       DEVICE_PARENT,
+       DRIVER_NORMAL,
+       DRIVER_PARENT,
+};
+
 #ifdef CONFIG_NUMA
 static inline int dev_to_node(struct device *dev)
 {
Index: linux-2.6-2/include/linux/usb.h
===================================================================
--- linux-2.6-2.orig/include/linux/usb.h
+++ linux-2.6-2/include/linux/usb.h
@@ -439,9 +439,9 @@ extern struct usb_device *usb_get_dev(st
 extern void usb_put_dev(struct usb_device *dev);
 
 /* USB device locking */
-#define usb_lock_device(udev)          down(&(udev)->dev.sem)
-#define usb_unlock_device(udev)                up(&(udev)->dev.sem)
-#define usb_trylock_device(udev)       down_trylock(&(udev)->dev.sem)
+#define usb_lock_device(udev)          mutex_lock(&(udev)->dev.mutex)
+#define usb_unlock_device(udev)                mutex_unlock(&(udev)->dev.mutex)
+#define usb_trylock_device(udev)       mutex_trylock(&(udev)->dev.mutex)
 extern int usb_lock_device_for_reset(struct usb_device *udev,
                                     const struct usb_interface *iface);
 

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to