On 06/10/2013 06:18 AM, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
> Subject: ACPI / scan: Simplify ACPI driver probing
>
> There is no particular reason why acpi_bus_driver_init() needs to be
> a separate function and its location with respect to its only caller,
> acpi_device_probe(), makes the code a bit difficult to follow.
>
> Besides, it doesn't really make sense to check if 'device' is not
> NULL in acpi_bus_driver_init(), because we've already dereferenced
> dev->driver in acpi_device_probe() at that point and, moreover,
> 'device' cannot be NULL then, because acpi_device_probe() is called
> via really_probe() (which also sets dev->driver for that matter).
>
> For these reasons, drop acpi_bus_driver_init() altogether and move
> the remaining code from it directly into acpi_device_probe().
Tested on one desktop and two laptops, no problems found.
Thanks,
Aaron
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
> ---
>
> It's in the bleeding-edge branch of the linux-pm.git tree already.
>
> Thanks,
> Rafael
>
> ---
> drivers/acpi/scan.c | 81
> +++++++++++++++++-----------------------------------
> 1 file changed, 27 insertions(+), 54 deletions(-)
>
> Index: linux-pm/drivers/acpi/scan.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/scan.c
> +++ linux-pm/drivers/acpi/scan.c
> @@ -933,32 +933,40 @@ static void acpi_device_remove_notify_ha
> acpi_device_notify);
> }
>
> -static int acpi_bus_driver_init(struct acpi_device *, struct acpi_driver *);
> -static int acpi_device_probe(struct device * dev)
> +static int acpi_device_probe(struct device *dev)
> {
> struct acpi_device *acpi_dev = to_acpi_device(dev);
> struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
> int ret;
>
> - ret = acpi_bus_driver_init(acpi_dev, acpi_drv);
> - if (!ret) {
> - if (acpi_drv->ops.notify) {
> - ret = acpi_device_install_notify_handler(acpi_dev);
> - if (ret) {
> - if (acpi_drv->ops.remove)
> - acpi_drv->ops.remove(acpi_dev);
> - acpi_dev->driver = NULL;
> - acpi_dev->driver_data = NULL;
> - return ret;
> - }
> - }
> + if (!acpi_drv->ops.add)
> + return -ENOSYS;
> +
> + ret = acpi_drv->ops.add(acpi_dev);
> + if (ret)
> + return ret;
>
> - ACPI_DEBUG_PRINT((ACPI_DB_INFO,
> - "Found driver [%s] for device [%s]\n",
> - acpi_drv->name, acpi_dev->pnp.bus_id));
> - get_device(dev);
> + acpi_dev->driver = acpi_drv;
> + ACPI_DEBUG_PRINT((ACPI_DB_INFO,
> + "Driver [%s] successfully bound to device [%s]\n",
> + acpi_drv->name, acpi_dev->pnp.bus_id));
> +
> + if (acpi_drv->ops.notify) {
> + ret = acpi_device_install_notify_handler(acpi_dev);
> + if (ret) {
> + if (acpi_drv->ops.remove)
> + acpi_drv->ops.remove(acpi_dev);
> +
> + acpi_dev->driver = NULL;
> + acpi_dev->driver_data = NULL;
> + return ret;
> + }
> }
> - return ret;
> +
> + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found driver [%s] for device [%s]\n",
> + acpi_drv->name, acpi_dev->pnp.bus_id));
> + get_device(dev);
> + return 0;
> }
>
> static int acpi_device_remove(struct device * dev)
> @@ -1114,41 +1122,6 @@ static void acpi_device_unregister(struc
> Driver Management
>
> -------------------------------------------------------------------------- */
> /**
> - * acpi_bus_driver_init - add a device to a driver
> - * @device: the device to add and initialize
> - * @driver: driver for the device
> - *
> - * Used to initialize a device via its device driver. Called whenever a
> - * driver is bound to a device. Invokes the driver's add() ops.
> - */
> -static int
> -acpi_bus_driver_init(struct acpi_device *device, struct acpi_driver *driver)
> -{
> - int result = 0;
> -
> - if (!device || !driver)
> - return -EINVAL;
> -
> - if (!driver->ops.add)
> - return -ENOSYS;
> -
> - result = driver->ops.add(device);
> - if (result)
> - return result;
> -
> - device->driver = driver;
> -
> - /*
> - * TBD - Configuration Management: Assign resources to device based
> - * upon possible configuration and currently allocated resources.
> - */
> -
> - ACPI_DEBUG_PRINT((ACPI_DB_INFO,
> - "Driver successfully bound to device\n"));
> - return 0;
> -}
> -
> -/**
> * acpi_bus_register_driver - register a driver with the ACPI bus
> * @driver: driver being registered
> *
>
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