Re: [PATCH -v4 1/2] PCIe: Add runtime PM support to PCIe port

Rafael J. Wysocki
2012-05-21T22:04:42Z

On Friday, May 18, 2012, Huang Ying wrote:
> From: "Yan, Zheng" <zheng.z.yan@intel.com>
>
> This patch adds runtime PM support to PCIe port. This is needed by
> PCIe D3cold support, where PCIe device without ACPI node may be
> powered on/off by PCIe port.
>
> Because runtime suspend is broken for some chipsets, a black list is
> used to disable runtime PM support for these chipsets.
>
> Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>

Reviewed-by: Rafael J. Wysocki <rjw@sisk.pl>

Thanks,
Rafael

> ---
> drivers/pci/pci.c | 10 ++++++++++
> drivers/pci/pcie/portdrv_pci.c | 24 ++++++++++++++++++++++++
> 2 files changed, 34 insertions(+)
>
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -1517,6 +1517,16 @@ static void pci_pme_list_scan(struct wor
> if (!list_empty(&pci_pme_list)) {
> list_for_each_entry_safe(pme_dev, n, &pci_pme_list, list) {
> if (pme_dev->dev->pme_poll) {
> + struct pci_dev *bridge;
> +
> + bridge = pme_dev->dev->bus->self;
> + /*
> + * If bridge is in low power state, the
> + * configuration space of subordinate devices
> + * may be not accessible
> + */
> + if (bridge && bridge->current_state != PCI_D0)
> + continue;
> pci_pme_wakeup(pme_dev->dev, NULL);
> } else {
> list_del(&pme_dev->list);
> --- a/drivers/pci/pcie/portdrv_pci.c
> +++ b/drivers/pci/pcie/portdrv_pci.c
> @@ -11,6 +11,7 @@
> #include <linux/kernel.h>
> #include <linux/errno.h>
> #include <linux/pm.h>
> +#include <linux/pm_runtime.h>
> #include <linux/init.h>
> #include <linux/pcieport_if.h>
> #include <linux/aer.h>
> @@ -99,6 +100,15 @@ static int pcie_port_resume_noirq(struct
> return 0;
> }
>
> +#ifdef CONFIG_PM_RUNTIME
> +static int pcie_port_runtime_pm(struct device *dev)
> +{
> + return 0;
> +}
> +#else
> +#define pcie_port_runtime_pm NULL
> +#endif
> +
> static const struct dev_pm_ops pcie_portdrv_pm_ops = {
> .suspend = pcie_port_device_suspend,
> .resume = pcie_port_device_resume,
> @@ -107,6 +117,8 @@ static const struct dev_pm_ops pcie_port
> .poweroff = pcie_port_device_suspend,
> .restore = pcie_port_device_resume,
> .resume_noirq = pcie_port_resume_noirq,
> + .runtime_suspend = pcie_port_runtime_pm,
> + .runtime_resume = pcie_port_runtime_pm,
> };
>
> #define PCIE_PORTDRV_PM_OPS (&pcie_portdrv_pm_ops)
> @@ -117,6 +129,14 @@ static const struct dev_pm_ops pcie_port
> #endif /* !PM */
>
> /*
> + * PCIe port runtime suspend is broken for some chipsets, so use a
> + * black list to disable runtime PM for these chipsets.
> + */
> +static const struct pci_device_id port_runtime_pm_black_list[] = {
> + { /* end: all zeroes */ }
> +};
> +
> +/*
> * pcie_portdrv_probe - Probe PCI-Express port devices
> * @dev: PCI-Express port device being probed
> *
> @@ -144,12 +164,16 @@ static int __devinit pcie_portdrv_probe(
> return status;
>
> pci_save_state(dev);
> + if (!pci_match_id(port_runtime_pm_black_list, dev))
> + pm_runtime_put_noidle(&dev->dev);
>
> return 0;
> }
>
> static void pcie_portdrv_remove(struct pci_dev *dev)
> {
> + if (!pci_match_id(port_runtime_pm_black_list, dev))
> + pm_runtime_get_noresume(&dev->dev);
> pcie_port_device_remove(dev);
> pci_disable_device(dev);
> }
>
>