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SubjectRe: [Xen-devel] [PATCH] xen: use PCI interfaces to request IO and MEM resources on platform device.
>>> On 11.01.11 at 12:50, Ian Campbell <ian.campbell@citrix.com> wrote:
> This is the correct interface to use and something has broken the use
> of the previous incorrect interface (which fails because the request
> conflicts with the resources assigned for the PCI device itself
> instead of nesting like the PCI interfaces do).

While I agree that using the PCI interface is preferable, I can't see
how this can make a functional difference: __pci_request_region()
calls request_region() for the port resource and
__request_mem_region() for the mmio one exactly like what was
open coded before (request_mem_region() being equivalent to
__request_mem_region(..., 0), so I don't follow how this fixes
anything but half of the potentially incorrect use of "long" for
mmio_addr.

I'm mainly asking because if it really addresses some problem,
then unmodified_drivers/linux-2.6/platform-pci/platform-pci.c
in -unstable should probably get updated too.

Jan

> Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
> Cc: stable@kernel.org # 2.6.37 only
> ---
> drivers/xen/platform-pci.c | 21 +++++++--------------
> 1 files changed, 7 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/xen/platform-pci.c b/drivers/xen/platform-pci.c
> index c01b5dd..afbe041 100644
> --- a/drivers/xen/platform-pci.c
> +++ b/drivers/xen/platform-pci.c
> @@ -105,7 +105,7 @@ static int __devinit platform_pci_init(struct pci_dev
> *pdev,
> const struct pci_device_id *ent)
> {
> int i, ret;
> - long ioaddr, iolen;
> + long ioaddr;
> long mmio_addr, mmio_len;
> unsigned int max_nr_gframes;
>
> @@ -114,7 +114,6 @@ static int __devinit platform_pci_init(struct pci_dev
> *pdev,
> return i;
>
> ioaddr = pci_resource_start(pdev, 0);
> - iolen = pci_resource_len(pdev, 0);
>
> mmio_addr = pci_resource_start(pdev, 1);
> mmio_len = pci_resource_len(pdev, 1);
> @@ -125,19 +124,13 @@ static int __devinit platform_pci_init(struct pci_dev
> *pdev,
> goto pci_out;
> }
>
> - if (request_mem_region(mmio_addr, mmio_len, DRV_NAME) == NULL) {
> - dev_err(&pdev->dev, "MEM I/O resource 0x%lx @ 0x%lx busy\n",
> - mmio_addr, mmio_len);
> - ret = -EBUSY;
> + ret = pci_request_region(pdev, 1, DRV_NAME);
> + if (ret < 0)
> goto pci_out;
> - }
>
> - if (request_region(ioaddr, iolen, DRV_NAME) == NULL) {
> - dev_err(&pdev->dev, "I/O resource 0x%lx @ 0x%lx busy\n",
> - iolen, ioaddr);
> - ret = -EBUSY;
> + ret = pci_request_region(pdev, 0, DRV_NAME);
> + if (ret < 0)
> goto mem_out;
> - }
>
> platform_mmio = mmio_addr;
> platform_mmiolen = mmio_len;
> @@ -169,9 +162,9 @@ static int __devinit platform_pci_init(struct pci_dev
> *pdev,
> return 0;
>
> out:
> - release_region(ioaddr, iolen);
> + pci_release_region(pdev, 0);
> mem_out:
> - release_mem_region(mmio_addr, mmio_len);
> + pci_release_region(pdev, 1);
> pci_out:
> pci_disable_device(pdev);
> return ret;






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