diff options
author | David Vrabel <david.vrabel@csr.com> | 2008-11-07 17:37:33 +0000 |
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committer | David Vrabel <david.vrabel@csr.com> | 2008-11-07 17:37:33 +0000 |
commit | 307ba6dd73254fe7d2ce27db64ffd90e1bb3c6c0 (patch) | |
tree | 535e10e6bd399c1f1d1f55a546e0c6aa92ba9dee /drivers/uwb/umc-bus.c | |
parent | fec1a5932f16c0eb1b3f5ca2e18d81d860924088 (diff) | |
download | kernel_samsung_smdk4412-307ba6dd73254fe7d2ce27db64ffd90e1bb3c6c0.zip kernel_samsung_smdk4412-307ba6dd73254fe7d2ce27db64ffd90e1bb3c6c0.tar.gz kernel_samsung_smdk4412-307ba6dd73254fe7d2ce27db64ffd90e1bb3c6c0.tar.bz2 |
uwb: don't unbind the radio controller driver when resetting
Use pre_reset and post_reset methods to avoid unbinding the radio
controller driver after a uwb_rc_reset_all() call. This avoids a
deadlock in uwb_rc_rm() when waiting for the uwb event thread to stop.
Signed-off-by: David Vrabel <david.vrabel@csr.com>
Diffstat (limited to 'drivers/uwb/umc-bus.c')
-rw-r--r-- | drivers/uwb/umc-bus.c | 62 |
1 files changed, 43 insertions, 19 deletions
diff --git a/drivers/uwb/umc-bus.c b/drivers/uwb/umc-bus.c index 2d8d62d..5ad3616 100644 --- a/drivers/uwb/umc-bus.c +++ b/drivers/uwb/umc-bus.c @@ -11,23 +11,48 @@ #include <linux/uwb/umc.h> #include <linux/pci.h> -static int umc_bus_unbind_helper(struct device *dev, void *data) +static int umc_bus_pre_reset_helper(struct device *dev, void *data) { - struct device *parent = data; + int ret = 0; - if (dev->parent == parent && dev->driver) - device_release_driver(dev); - return 0; + if (dev->driver) { + struct umc_dev *umc = to_umc_dev(dev); + struct umc_driver *umc_drv = to_umc_driver(dev->driver); + + if (umc_drv->pre_reset) + ret = umc_drv->pre_reset(umc); + else + device_release_driver(dev); + } + return ret; +} + +static int umc_bus_post_reset_helper(struct device *dev, void *data) +{ + int ret = 0; + + if (dev->driver) { + struct umc_dev *umc = to_umc_dev(dev); + struct umc_driver *umc_drv = to_umc_driver(dev->driver); + + if (umc_drv->post_reset) + ret = umc_drv->post_reset(umc); + } else + ret = device_attach(dev); + + return ret; } /** * umc_controller_reset - reset the whole UMC controller * @umc: the UMC device for the radio controller. * - * Drivers will be unbound from all UMC devices belonging to the - * controller and then the radio controller will be rebound. The - * radio controller is expected to do a full hardware reset when it is - * probed. + * Drivers or all capabilities of the controller will have their + * pre_reset methods called or be unbound from their device. Then all + * post_reset methods will be called or the drivers will be rebound. + * + * Radio controllers must provide pre_reset and post_reset methods and + * reset the hardware in their start method. * * If this is called while a probe() or remove() is in progress it * will return -EAGAIN and not perform the reset. @@ -35,14 +60,13 @@ static int umc_bus_unbind_helper(struct device *dev, void *data) int umc_controller_reset(struct umc_dev *umc) { struct device *parent = umc->dev.parent; - int ret; + int ret = 0; - if (down_trylock(&parent->sem)) + if(down_trylock(&parent->sem)) return -EAGAIN; - bus_for_each_dev(&umc_bus_type, NULL, parent, umc_bus_unbind_helper); - ret = device_attach(&umc->dev); - if (ret == 1) - ret = 0; + ret = device_for_each_child(parent, parent, umc_bus_pre_reset_helper); + if (ret >= 0) + device_for_each_child(parent, parent, umc_bus_post_reset_helper); up(&parent->sem); return ret; @@ -75,10 +99,10 @@ static int umc_bus_rescan_helper(struct device *dev, void *data) if (!dev->driver) ret = device_attach(dev); - return ret < 0 ? ret : 0; + return ret; } -static void umc_bus_rescan(void) +static void umc_bus_rescan(struct device *parent) { int err; @@ -86,7 +110,7 @@ static void umc_bus_rescan(void) * We can't use bus_rescan_devices() here as it deadlocks when * it tries to retake the dev->parent semaphore. */ - err = bus_for_each_dev(&umc_bus_type, NULL, NULL, umc_bus_rescan_helper); + err = device_for_each_child(parent, NULL, umc_bus_rescan_helper); if (err < 0) printk(KERN_WARNING "%s: rescan of bus failed: %d\n", KBUILD_MODNAME, err); @@ -120,7 +144,7 @@ static int umc_device_probe(struct device *dev) if (err) put_device(dev); else - umc_bus_rescan(); + umc_bus_rescan(dev->parent); return err; } |