This reverts commit fe9a743a2601 ("PCI/PM: Drop unused runtime
PM support code for PCIe ports"). To support PCIe ports
runtime PM for Intel Broxton platform.

Signed-off-by: Qi Zheng <qi.zh...@intel.com>
Signed-off-by: Qipeng Zha <qipeng....@intel.com>
---
 drivers/pci/pcie/portdrv_pci.c | 68 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)

diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c
index be35da2..1e4a562 100644
--- a/drivers/pci/pcie/portdrv_pci.c
+++ b/drivers/pci/pcie/portdrv_pci.c
@@ -93,6 +93,71 @@ static int pcie_port_resume_noirq(struct device *dev)
        return 0;
 }
 
+struct d3cold_info {
+       bool no_d3cold;
+       unsigned int d3cold_delay;
+};
+
+static int pci_dev_d3cold_info(struct pci_dev *pdev, void *data)
+{
+       struct d3cold_info *info = data;
+
+       info->d3cold_delay = max_t(unsigned int, pdev->d3cold_delay,
+                                  info->d3cold_delay);
+       if (pdev->no_d3cold)
+               info->no_d3cold = true;
+       return 0;
+}
+
+static int pcie_port_runtime_suspend(struct device *dev)
+{
+       struct pci_dev *pdev = to_pci_dev(dev);
+       struct d3cold_info d3cold_info = {
+               .no_d3cold      = false,
+               .d3cold_delay   = PCI_PM_D3_WAIT,
+       };
+
+       /*
+        * If any subordinate device disable D3cold, we should not put
+        * the port into D3cold.  The D3cold delay of port should be
+        * the max of that of all subordinate devices.
+        */
+       pci_walk_bus(pdev->subordinate, pci_dev_d3cold_info, &d3cold_info);
+       pdev->no_d3cold = d3cold_info.no_d3cold;
+       pdev->d3cold_delay = d3cold_info.d3cold_delay;
+       return 0;
+}
+
+static int pcie_port_runtime_resume(struct device *dev)
+{
+       return 0;
+}
+
+static int pci_dev_pme_poll(struct pci_dev *pdev, void *data)
+{
+       bool *pme_poll = data;
+
+       if (pdev->pme_poll)
+               *pme_poll = true;
+       return 0;
+}
+
+static int pcie_port_runtime_idle(struct device *dev)
+{
+       struct pci_dev *pdev = to_pci_dev(dev);
+       bool pme_poll = false;
+
+       /*
+        * If any subordinate device needs pme poll, we should keep
+        * the port in D0, because we need port in D0 to poll it.
+        */
+       pci_walk_bus(pdev->subordinate, pci_dev_pme_poll, &pme_poll);
+       /* Delay for a short while to prevent too frequent suspend/resume */
+       if (!pme_poll)
+               pm_schedule_suspend(dev, 10);
+       return -EBUSY;
+}
+
 static const struct dev_pm_ops pcie_portdrv_pm_ops = {
        .suspend        = pcie_port_device_suspend,
        .resume         = pcie_port_device_resume,
@@ -101,6 +166,9 @@ static const struct dev_pm_ops pcie_portdrv_pm_ops = {
        .poweroff       = pcie_port_device_suspend,
        .restore        = pcie_port_device_resume,
        .resume_noirq   = pcie_port_resume_noirq,
+       .runtime_suspend = pcie_port_runtime_suspend,
+       .runtime_resume = pcie_port_runtime_resume,
+       .runtime_idle   = pcie_port_runtime_idle,
 };
 
 #define PCIE_PORTDRV_PM_OPS    (&pcie_portdrv_pm_ops)
-- 
1.8.3.2

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