Re: [RFC 1/4] PCI: Add hooks to allocate/free IRQ resources when binding/unbinding driver

From: Bjorn Helgaas
Date: Tue May 19 2015 - 10:46:11 EST


On Thu, May 07, 2015 at 11:12:51AM +0800, Jiang Liu wrote:
> Add two hook points pcibios_{alloc|free}_irq() into PCI core, which will
> be called when binding/unbinding PCI device drivers. Then PCI arch code
> may hook into these two points to allocate IRQ resources on demand and
> free them when not used anymore.
>
> Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
> ---
> drivers/pci/pci-driver.c | 33 +++++++++++++++++++++++----------
> include/linux/pci.h | 2 ++
> 2 files changed, 25 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
> index 3cb2210de553..8af4a671686f 100644
> --- a/drivers/pci/pci-driver.c
> +++ b/drivers/pci/pci-driver.c
> ...
> +static int pci_device_probe(struct device *dev)
> +{
> + int error;
> + struct pci_dev *pci_dev = to_pci_dev(dev);
> + struct pci_driver *drv = to_pci_driver(dev->driver);
> +
> + error = pcibios_alloc_irq(pci_dev);
> + if (error >= 0) {
> + pci_dev_get(pci_dev);
> + error = __pci_device_probe(drv, pci_dev);
> + if (error) {
> + pcibios_free_irq(pci_dev);
> + pci_dev_put(pci_dev);
> + }
> + }

Please structure it like this so the mainline code doesn't get buried in
the body of the "if":

irq = pcibios_alloc_irq(pci_dev);
if (irq < 0)
return irq;

pci_dev_get(pci_dev);
...

>
> return error;
> }
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