Patchwork [RFC,v1,03/22] PCI: change PCI device management code to better follow device model

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Submitter Jiang Liu
Date Aug. 7, 2012, 4:10 p.m.
Message ID <1344355862-2726-4-git-send-email-jiang.liu@huawei.com>
Download mbox | patch
Permalink /patch/175700/
State Not Applicable
Headers show

Comments

Jiang Liu - Aug. 7, 2012, 4:10 p.m.
According to device model documentation, the way to add/remove device
object should be symmetric.

/**
 * device_del - delete device from system.
 * @dev: device.
 *
 * This is the first part of the device unregistration
 * sequence. This removes the device from the lists we control
 * from here, has it removed from the other driver model
 * subsystems it was added to in device_add(), and removes it
 * from the kobject hierarchy.
 *
 * NOTE: this should be called manually _iff_ device_add() was
 * also called manually.
 */

The rule here is to either use
1) device_register()/device_unregister()
or
2) device_initialize()/device_add()/device_del()/put_device().

So change PCI core to follow the rule and get rid of the redundant
pci_dev_get()/pci_dev_put() pair.

Signed-off-by: Jiang Liu <liuj97@gmail.com>
---
 drivers/pci/probe.c  |    1 -
 drivers/pci/remove.c |    4 ++--
 2 files changed, 2 insertions(+), 3 deletions(-)
Bjorn Helgaas - Sept. 11, 2012, 10:03 p.m.
On Tue, Aug 7, 2012 at 10:10 AM, Jiang Liu <liuj97@gmail.com> wrote:
> According to device model documentation, the way to add/remove device
> object should be symmetric.
>
> /**
>  * device_del - delete device from system.
>  * @dev: device.
>  *
>  * This is the first part of the device unregistration
>  * sequence. This removes the device from the lists we control
>  * from here, has it removed from the other driver model
>  * subsystems it was added to in device_add(), and removes it
>  * from the kobject hierarchy.
>  *
>  * NOTE: this should be called manually _iff_ device_add() was
>  * also called manually.
>  */
>
> The rule here is to either use
> 1) device_register()/device_unregister()
> or
> 2) device_initialize()/device_add()/device_del()/put_device().
>
> So change PCI core to follow the rule and get rid of the redundant
> pci_dev_get()/pci_dev_put() pair.

Seems OK to me.

> Signed-off-by: Jiang Liu <liuj97@gmail.com>
> ---
>  drivers/pci/probe.c  |    1 -
>  drivers/pci/remove.c |    4 ++--
>  2 files changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 0840409..dacca26 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1294,7 +1294,6 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
>  {
>         device_initialize(&dev->dev);
>         dev->dev.release = pci_release_dev;
> -       pci_dev_get(dev);
>
>         dev->dev.dma_mask = &dev->dma_mask;
>         dev->dev.dma_parms = &dev->dma_parms;
> diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
> index 33b6318..b9ac765 100644
> --- a/drivers/pci/remove.c
> +++ b/drivers/pci/remove.c
> @@ -22,7 +22,7 @@ static void pci_stop_dev(struct pci_dev *dev)
>         if (dev->is_added) {
>                 pci_proc_detach_device(dev);
>                 pci_remove_sysfs_dev_files(dev);
> -               device_unregister(&dev->dev);
> +               device_del(&dev->dev);
>                 dev->is_added = 0;
>         }
>
> @@ -40,7 +40,7 @@ static void pci_destroy_dev(struct pci_dev *dev)
>         up_write(&pci_bus_sem);
>
>         pci_free_resources(dev);
> -       pci_dev_put(dev);
> +       put_device(&dev->dev);
>  }
>
>  /**
> --
> 1.7.9.5
>
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Patch

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 0840409..dacca26 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1294,7 +1294,6 @@  void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
 {
 	device_initialize(&dev->dev);
 	dev->dev.release = pci_release_dev;
-	pci_dev_get(dev);
 
 	dev->dev.dma_mask = &dev->dma_mask;
 	dev->dev.dma_parms = &dev->dma_parms;
diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
index 33b6318..b9ac765 100644
--- a/drivers/pci/remove.c
+++ b/drivers/pci/remove.c
@@ -22,7 +22,7 @@  static void pci_stop_dev(struct pci_dev *dev)
 	if (dev->is_added) {
 		pci_proc_detach_device(dev);
 		pci_remove_sysfs_dev_files(dev);
-		device_unregister(&dev->dev);
+		device_del(&dev->dev);
 		dev->is_added = 0;
 	}
 
@@ -40,7 +40,7 @@  static void pci_destroy_dev(struct pci_dev *dev)
 	up_write(&pci_bus_sem);
 
 	pci_free_resources(dev);
-	pci_dev_put(dev);
+	put_device(&dev->dev);
 }
 
 /**