Re: [PATCH v8 21/22] PCI: add match_driver in struct pci_dev

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Friday, January 11, 2013 02:40:48 PM Yinghai Lu wrote:
> with that we could move out attaching driver for pci device,
> out of device_add for pci hot add path.
> 
> pci_bus_attach_device() will attach driver to pci device.

Clever, but I wonder why exactly we need to do that?

Rafael


> Signed-off-by: Yinghai Lu <yinghai@kernel.org>
> ---
>  drivers/pci/bus.c        |   10 ++++++++++
>  drivers/pci/pci-driver.c |    6 +++++-
>  include/linux/pci.h      |    1 +
>  3 files changed, 16 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
> index 5f9c728..1f5916a 100644
> --- a/drivers/pci/bus.c
> +++ b/drivers/pci/bus.c
> @@ -160,6 +160,15 @@ pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
>  
>  void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { }
>  
> +static void pci_bus_attach_device(struct pci_dev *dev)
> +{
> +	int ret;
> +
> +	dev->match_driver = true;
> +	ret = device_attach(&dev->dev);
> +	WARN_ON(ret < 0);
> +}
> +
>  /**
>   * pci_bus_add_device - add a single device
>   * @dev: device to add
> @@ -181,6 +190,7 @@ int pci_bus_add_device(struct pci_dev *dev)
>  	if (retval)
>  		return retval;
>  
> +	pci_bus_attach_device(dev);
>  	dev->is_added = 1;
>  	pci_proc_attach_device(dev);
>  	pci_create_sysfs_dev_files(dev);
> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
> index f79cbcd..acdcc3c 100644
> --- a/drivers/pci/pci-driver.c
> +++ b/drivers/pci/pci-driver.c
> @@ -1186,9 +1186,13 @@ pci_dev_driver(const struct pci_dev *dev)
>  static int pci_bus_match(struct device *dev, struct device_driver *drv)
>  {
>  	struct pci_dev *pci_dev = to_pci_dev(dev);
> -	struct pci_driver *pci_drv = to_pci_driver(drv);
> +	struct pci_driver *pci_drv;
>  	const struct pci_device_id *found_id;
>  
> +	if (!pci_dev->match_driver)
> +		return 0;
> +
> +	pci_drv = to_pci_driver(drv);
>  	found_id = pci_match_device(pci_drv, pci_dev);
>  	if (found_id)
>  		return 1;
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 907b455..d73af08 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -286,6 +286,7 @@ struct pci_dev {
>  	unsigned int	irq;
>  	struct resource resource[DEVICE_COUNT_RESOURCE]; /* I/O and memory regions + expansion ROMs */
>  
> +	bool match_driver;
>  	/* These fields are used by common fixups */
>  	unsigned int	transparent:1;	/* Transparent PCI bridge */
>  	unsigned int	multifunction:1;/* Part of multi-function device */
> 
-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.