Re: [RFC PATCH v11 4/5] PCI / PM: Add support for the PCIe WAKE# signal for OF

Rafael J. Wysocki
2017-12-26T00:12:23Z

On Monday, December 25, 2017 12:47:41 PM CET Jeffy Chen wrote:
> Add of_pci_setup_wake_irq() and of_pci_teardown_wake_irq() to handle
> the PCIe WAKE# interrupt.
>
> Also use the dedicated wakeirq infrastructure to simplify it.
>
> Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
> ---
>
> Changes in v11:
> Only support 1-per-device PCIe WAKE# pin as suggested.
>
> Changes in v10:
> Use device_set_wakeup_capable() instead of device_set_wakeup_enable(),
> since dedicated wakeirq will be lost in device_set_wakeup_enable(false).
>
> Changes in v9:
> Fix check error in .cleanup().
> Move dedicated wakeirq setup to setup() callback and use
> device_set_wakeup_enable() to enable/disable.
>
> Changes in v8:
> Add pci-of.c and use platform_pm_ops to handle the PCIe WAKE# signal.
>
> Changes in v7:
> Move PCIE_WAKE handling into pci core.
>
> Changes in v6:
> Fix device_init_wake error handling, and add some comments.
>
> Changes in v5:
> Rebase.
>
> Changes in v3:
> Fix error handling.
>
> Changes in v2:
> Use dev_pm_set_dedicated_wake_irq.
>
> drivers/of/of_pci_irq.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++
> drivers/pci/pci-driver.c | 10 ++++++++++
> include/linux/of_pci.h | 9 +++++++++
> 3 files changed, 68 insertions(+)
>
> diff --git a/drivers/of/of_pci_irq.c b/drivers/of/of_pci_irq.c
> index d39565d5477b..def884c1a37a 100644
> --- a/drivers/of/of_pci_irq.c
> +++ b/drivers/of/of_pci_irq.c
> @@ -1,8 +1,57 @@
> #include <linux/kernel.h>
> #include <linux/of_pci.h>
> #include <linux/of_irq.h>
> +#include <linux/pm_wakeirq.h>
> #include <linux/export.h>
>
> +int of_pci_setup_wake_irq(struct pci_dev *pdev)
> +{
> + struct pci_dev *ppdev;
> + struct device_node *dn;
> + int ret, irq;
> +
> + /* Get the pci_dev of our parent. Hopefully it's a port. */
> + ppdev = pdev->bus->self;
> + /* Nope, it's a host bridge. */
> + if (!ppdev)
> + return 0;
> +
> + dn = pci_device_to_OF_node(ppdev);
> + if (!dn)
> + return 0;
> +
> + irq = of_irq_get_byname(dn, "wakeup");

Why is this a property of the bridge and not of the device itself?

> + if (irq == -EPROBE_DEFER)

Braces here, please.

> + return irq;
> + /* Ignore other errors, since a missing wakeup is non-fatal. */
> + else if (irq < 0) {
> + dev_info(&pdev->dev, "cannot get wakeup interrupt: %d\n", irq);
> + return 0;
> + }
> +
> + device_init_wakeup(&pdev->dev, true);

Why do you call this before dev_pm_set_dedicated_wake_irq()?

> +
> + ret = dev_pm_set_dedicated_wake_irq(&pdev->dev, irq);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "failed to set wake IRQ: %d\n", ret);
> + device_init_wakeup(&pdev->dev, false);
> + return ret;
> + }
> +

It would be more straightforward to call device_init_wakeup() here.

> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(of_pci_setup_wake_irq);
> +
> +void of_pci_teardown_wake_irq(struct pci_dev *pdev)
> +{
> + if (!pdev->dev.power.wakeirq)
> + return;
> +
> + dev_pm_clear_wake_irq(&pdev->dev);
> + device_init_wakeup(&pdev->dev, false);
> +}
> +EXPORT_SYMBOL_GPL(of_pci_teardown_wake_irq);
> +
> /**
> * of_irq_parse_pci - Resolve the interrupt for a PCI device
> * @pdev: the device whose interrupt is to be resolved

Thanks,
Rafael