From 016599f589a50feee9f515dc1e7879e390ae229f Mon Sep 17 00:00:00 2001 From: Ian Abbott Date: Thu, 4 Apr 2013 14:58:58 +0100 Subject: [PATCH] staging: comedi: replace __comedi_device_detach() `comedi_device_detach()` does nothing if the `struct comedi_device`'s `attached` member is false, otherwise it calls `__comedi_device_detach()` to do the real work. `__comedi_device_detach()` is called from various other functions in "drivers.c" (`comedi_device_postconfig()`, `comedi_device_attach()`, and `comedi_auto_config()`) to bypass the check for the `attached` member being false. If we make `__comedi_device_detach()` safe to call when the `attached` member is already false, we can remove the check in `comedi_device_detach()`, subsume `__comedi_device_detach()` within `comedi_device_detach()`, and replace all the calls to `__comedi_device_detach()` with calls to `comedi_device_detach()`. In fact, it is already safe to call `__comedi_device_detach()` when the `attached` member is false. We just need to remove the warning message it outputs when the `driver` member is NULL. Then the function becomes idempotent without outputting spurious warnings. (It is idempotent because `dev->driver->detach()` will only be called once at most and the call to `cleanup_device()` is idempotent itself.) Combine `comedi_device_detach()` with `__comedi_device_detach()`, removing the check for the `attached` member being false and removing the warning about the `driver` member being NULL, and replace all calls to `__comedi_device_detach()` with calls to the combined `comedi_device_detach()`. A beneficial side-effect of the above change is that a call to `comedi_device_detach()` will always result in a call to `cleanup_device()` and so always result in a call to `comedi_clear_hw_dev()`. We will make use of this beneficial side-effect in a later patch. Signed-off-by: Ian Abbott Reviewed-by: H Hartley Sweeten Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers.c | 18 ++++-------------- 1 file changed, 4 insertions(+), 14 deletions(-) diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c index 6f232b8128c0..cf1ca822a2ce 100644 --- a/drivers/staging/comedi/drivers.c +++ b/drivers/staging/comedi/drivers.c @@ -119,24 +119,14 @@ static void cleanup_device(struct comedi_device *dev) comedi_clear_hw_dev(dev); } -static void __comedi_device_detach(struct comedi_device *dev) +void comedi_device_detach(struct comedi_device *dev) { dev->attached = false; if (dev->driver) dev->driver->detach(dev); - else - dev_warn(dev->class_dev, - "BUG: dev->driver=NULL in comedi_device_detach()\n"); cleanup_device(dev); } -void comedi_device_detach(struct comedi_device *dev) -{ - if (!dev->attached) - return; - __comedi_device_detach(dev); -} - static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s) { return -EINVAL; @@ -283,7 +273,7 @@ static int comedi_device_postconfig(struct comedi_device *dev) ret = __comedi_device_postconfig(dev); if (ret < 0) { - __comedi_device_detach(dev); + comedi_device_detach(dev); return ret; } if (!dev->board_name) { @@ -396,7 +386,7 @@ int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it) dev->driver = driv; ret = driv->attach(dev, it); if (ret < 0) { - __comedi_device_detach(dev); + comedi_device_detach(dev); module_put(dev->driver->module); return ret; } @@ -439,7 +429,7 @@ int comedi_auto_config(struct device *hardware_device, comedi_dev->driver = driver; ret = driver->auto_attach(comedi_dev, context); if (ret < 0) - __comedi_device_detach(comedi_dev); + comedi_device_detach(comedi_dev); else ret = comedi_device_postconfig(comedi_dev); mutex_unlock(&comedi_dev->mutex); -- GitLab