From 49b420a13ff95b449947181190b08367348e3e1b Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Wed, 21 Jan 2009 23:27:47 +0800 Subject: driver core: check bus->match without holding device lock This patch moves bus->match out from driver_probe_device and does not hold device lock to check the match between a device and a driver. The idea has been verified by the commit 6cd495860901, which leads to a faster boot. But the commit 6cd495860901 has the following drawbacks: 1),only does the quick check in the path of __driver_attach->driver_probe_device, not in other paths; 2),for a matched device and driver, check the same match twice. It is a waste of cpu ,especially for some drivers with long device id table (eg. usb-storage driver). This patch adds a helper of driver_match_device to check the match in all paths, and testes the match only once. Signed-off-by: Ming Lei Acked-by: Cornelia Huck Signed-off-by: Greg Kroah-Hartman --- drivers/base/dd.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-) (limited to 'drivers/base/dd.c') diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 13523123910..3f32df7ed37 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -189,14 +189,8 @@ int wait_for_device_probe(void) * @drv: driver to bind a device to * @dev: device to try to bind to the driver * - * First, we call the bus's match function, if one present, which should - * compare the device IDs the driver supports with the device IDs of the - * device. Note we don't do this ourselves because we don't know the - * format of the ID structures, nor what is to be considered a match and - * what is not. - * - * This function returns 1 if a match is found, -ENODEV if the device is - * not registered, and 0 otherwise. + * This function returns -ENODEV if the device is not registered, + * 1 if the device is bound sucessfully 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. @@ -207,21 +201,22 @@ int driver_probe_device(struct device_driver *drv, struct device *dev) if (!device_is_registered(dev)) return -ENODEV; - if (drv->bus->match && !drv->bus->match(dev, drv)) - goto done; pr_debug("bus: '%s': %s: matched device %s with driver %s\n", drv->bus->name, __func__, dev_name(dev), drv->name); ret = really_probe(dev, drv); -done: return ret; } static int __device_attach(struct device_driver *drv, void *data) { struct device *dev = data; + + if (!driver_match_device(drv, dev)) + return 0; + return driver_probe_device(drv, dev); } @@ -274,7 +269,7 @@ static int __driver_attach(struct device *dev, void *data) * is an error. */ - if (drv->bus->match && !drv->bus->match(dev, drv)) + if (!driver_match_device(drv, dev)) return 0; if (dev->parent) /* Needed for USB */ -- cgit v1.2.3 From b23530ebc339c4092ae2c9f37341a5398fea8b89 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Sat, 21 Feb 2009 16:45:07 +0800 Subject: driver core: remove polling for driver_probe_done(v5) This patch removes 100ms polling for driver_probe_done in wait_for_device_probe(), and uses wait_event() instead. Removing polling in fs initialization may lead to a faster boot. This patch also changes the return type of wait_for_device_done() from int to void. This patch is against Arjan's patch in linux-next tree. Signed-off-by: Ming Lei Acked-by: Cornelia Huck Reviewed-by: Arjan van de Ven Signed-off-by: Greg Kroah-Hartman --- drivers/base/dd.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) (limited to 'drivers/base/dd.c') diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 3f32df7ed37..0dfd08c1592 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -172,16 +172,12 @@ int driver_probe_done(void) /** * wait_for_device_probe * Wait for device probing to be completed. - * - * Note: this function polls at 100 msec intervals. */ -int wait_for_device_probe(void) +void wait_for_device_probe(void) { /* wait for the known devices to complete their probing */ - while (driver_probe_done() != 0) - msleep(100); + wait_event(probe_waitqueue, atomic_read(&probe_count) == 0); async_synchronize_full(); - return 0; } /** -- cgit v1.2.3 From 8940b4f312dced51b45004819b776ec3aa7fcd5d Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Tue, 16 Dec 2008 12:25:49 -0800 Subject: driver core: move knode_driver into private structure Nothing outside of the driver core should ever touch knode_driver, so move it out of the public eye. Cc: Kay Sievers Signed-off-by: Greg Kroah-Hartman --- drivers/base/dd.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) (limited to 'drivers/base/dd.c') diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 0dfd08c1592..f17c3266a0e 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -30,7 +30,7 @@ static void driver_bound(struct device *dev) { - if (klist_node_attached(&dev->knode_driver)) { + if (klist_node_attached(&dev->p->knode_driver)) { printk(KERN_WARNING "%s: device %s already bound\n", __func__, kobject_name(&dev->kobj)); return; @@ -43,7 +43,7 @@ static void driver_bound(struct device *dev) blocking_notifier_call_chain(&dev->bus->p->bus_notifier, BUS_NOTIFY_BOUND_DRIVER, dev); - klist_add_tail(&dev->knode_driver, &dev->driver->p->klist_devices); + klist_add_tail(&dev->p->knode_driver, &dev->driver->p->klist_devices); } static int driver_sysfs_add(struct device *dev) @@ -318,7 +318,7 @@ static void __device_release_driver(struct device *dev) drv->remove(dev); devres_release_all(dev); dev->driver = NULL; - klist_remove(&dev->knode_driver); + klist_remove(&dev->p->knode_driver); } } @@ -348,6 +348,7 @@ EXPORT_SYMBOL_GPL(device_release_driver); */ void driver_detach(struct device_driver *drv) { + struct device_private *dev_prv; struct device *dev; for (;;) { @@ -356,8 +357,10 @@ void driver_detach(struct device_driver *drv) spin_unlock(&drv->p->klist_devices.k_lock); break; } - dev = list_entry(drv->p->klist_devices.k_list.prev, - struct device, knode_driver.n_node); + dev_prv = list_entry(drv->p->klist_devices.k_list.prev, + struct device_private, + knode_driver.n_node); + dev = dev_prv->device; get_device(dev); spin_unlock(&drv->p->klist_devices.k_lock); -- cgit v1.2.3