Re: [PATCH 2/7] PCI: move resources and bus_list releasing to pci_release_dev

From: Yijing Wang
Date: Mon May 13 2013 - 23:21:06 EST


On 2013/5/14 10:28, Yinghai Lu wrote:
> We should not release resource in pci_destroy that is too early

Hi Yinghai,
"too early" means that after pci_stop_dev(), if someone else
hold the device reference, it still care the device resource ? e.g.?

Thanks!
Yijing.

> as there could be still other use hold reference.
>
> release them or remove it from bus devices list at last
> in pci_release_dev instead.
>
> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
>
> ---
> drivers/pci/probe.c | 20 ++++++++++++++++++++
> drivers/pci/remove.c | 19 -------------------
> 2 files changed, 20 insertions(+), 19 deletions(-)
>
> Index: linux-2.6/drivers/pci/probe.c
> ===================================================================
> --- linux-2.6.orig/drivers/pci/probe.c
> +++ linux-2.6/drivers/pci/probe.c
> @@ -1118,6 +1118,20 @@ static void pci_release_capabilities(str
> pci_free_cap_save_buffers(dev);
> }
>
> +static void pci_free_resources(struct pci_dev *dev)
> +{
> + int i;
> +
> + msi_remove_pci_irq_vectors(dev);
> +
> + pci_cleanup_rom(dev);
> + for (i = 0; i < PCI_NUM_RESOURCES; i++) {
> + struct resource *res = dev->resource + i;
> + if (res->parent)
> + release_resource(res);
> + }
> +}
> +
> /**
> * pci_release_dev - free a pci device structure when all users of it are finished.
> * @dev: device that's been disconnected
> @@ -1130,6 +1144,12 @@ static void pci_release_dev(struct devic
> struct pci_dev *pci_dev;
>
> pci_dev = to_pci_dev(dev);
> +
> + down_write(&pci_bus_sem);
> + list_del(&pci_dev->bus_list);
> + up_write(&pci_bus_sem);
> + pci_free_resources(pci_dev);
> +
> pci_release_capabilities(pci_dev);
> pci_release_of_node(pci_dev);
> kfree(pci_dev);
> Index: linux-2.6/drivers/pci/remove.c
> ===================================================================
> --- linux-2.6.orig/drivers/pci/remove.c
> +++ linux-2.6/drivers/pci/remove.c
> @@ -3,20 +3,6 @@
> #include <linux/pci-aspm.h>
> #include "pci.h"
>
> -static void pci_free_resources(struct pci_dev *dev)
> -{
> - int i;
> -
> - msi_remove_pci_irq_vectors(dev);
> -
> - pci_cleanup_rom(dev);
> - for (i = 0; i < PCI_NUM_RESOURCES; i++) {
> - struct resource *res = dev->resource + i;
> - if (res->parent)
> - release_resource(res);
> - }
> -}
> -
> static void pci_stop_dev(struct pci_dev *dev)
> {
> pci_pme_active(dev, false);
> @@ -34,11 +20,6 @@ static void pci_stop_dev(struct pci_dev
>
> static void pci_destroy_dev(struct pci_dev *dev)
> {
> - down_write(&pci_bus_sem);
> - list_del(&dev->bus_list);
> - up_write(&pci_bus_sem);
> -
> - pci_free_resources(dev);
> put_device(&dev->dev);
> }
>
> --
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> .
>


--
Thanks!
Yijing

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