PCI PM: Restore standard config registers of all devices early

[mirror_ubuntu-bionic-kernel.git] / drivers / pci / pci.c

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e491fdedf705279c98898e3d647bcf12d596b596..17bd9325a245333f4400676ceed18fe58d2f6a34 100644 (file)
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -22,7 +22,7 @@
 #include <asm/dma.h>   /* isa_dma_bridge_buggy */
 #include "pci.h"
 
-unsigned int pci_pm_d3_delay = 10;
+unsigned int pci_pm_d3_delay = PCI_PM_D3_WAIT;
 
 #ifdef CONFIG_PCI_DOMAINS
 int pci_domains_supported = 1;
@@ -426,6 +426,7 @@ static inline int platform_pci_sleep_wake(struct pci_dev *dev, bool enable)
  *                           given PCI device
  * @dev: PCI device to handle.
  * @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
+ * @wait: If 'true', wait for the device to change its power state
  *
  * RETURN VALUE:
  * -EINVAL if the requested state is invalid.
@@ -435,7 +436,7 @@ static inline int platform_pci_sleep_wake(struct pci_dev *dev, bool enable)
  * 0 if device's power state has been successfully changed.
  */
 static int
-pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
+pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state, bool wait)
 {
        u16 pmcsr;
        bool need_restore = false;
@@ -480,8 +481,10 @@ pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
                break;
        case PCI_UNKNOWN: /* Boot-up */
                if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
-                && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
+                && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET)) {
                        need_restore = true;
+                       wait = true;
+               }
                /* Fall-through: force to D0 */
        default:
                pmcsr = 0;
@@ -491,12 +494,15 @@ pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
        /* enter specified state */
        pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
 
+       if (!wait)
+               return 0;
+
        /* Mandatory power management transition delays */
        /* see PCI PM 1.1 5.6.1 table 18 */
        if (state == PCI_D3hot || dev->current_state == PCI_D3hot)
                msleep(pci_pm_d3_delay);
        else if (state == PCI_D2 || dev->current_state == PCI_D2)
-               udelay(200);
+               udelay(PCI_PM_D2_DELAY);
 
        dev->current_state = state;
 
@@ -515,7 +521,7 @@ pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
        if (need_restore)
                pci_restore_bars(dev);
 
-       if (dev->bus->self)
+       if (wait && dev->bus->self)
                pcie_aspm_pm_state_change(dev->bus->self);
 
        return 0;
@@ -585,7 +591,7 @@ int pci_set_power_state(struct pci_dev *dev, pci_power_t state)
        if (state == PCI_D3hot && (dev->dev_flags & PCI_DEV_FLAGS_NO_D3))
                return 0;
 
-       error = pci_raw_set_power_state(dev, state);
+       error = pci_raw_set_power_state(dev, state, true);
 
        if (state > PCI_D0 && platform_pci_power_manageable(dev)) {
                /* Allow the platform to finalize the transition */
@@ -730,6 +736,7 @@ pci_save_state(struct pci_dev *dev)
        /* XXX: 100% dword access ok here? */
        for (i = 0; i < 16; i++)
                pci_read_config_dword(dev, i * 4,&dev->saved_config_space[i]);
+       dev->state_saved = true;
        if ((i = pci_save_pcie_state(dev)) != 0)
                return i;
        if ((i = pci_save_pcix_state(dev)) != 0)
@@ -1373,6 +1380,50 @@ void pci_allocate_cap_save_buffers(struct pci_dev *dev)
                        "unable to preallocate PCI-X save buffer\n");
 }
 
+/**
+ * pci_restore_standard_config - restore standard config registers of PCI device
+ * @dev: PCI device to handle
+ *
+ * This function assumes that the device's configuration space is accessible.
+ * If the device needs to be powered up, the function will wait for it to
+ * change the state.
+ */
+int pci_restore_standard_config(struct pci_dev *dev)
+{
+       pci_power_t prev_state;
+       int error;
+
+       pci_restore_state(dev);
+       pci_update_current_state(dev, PCI_D0);
+
+       prev_state = dev->current_state;
+       if (prev_state == PCI_D0)
+               return 0;
+
+       error = pci_raw_set_power_state(dev, PCI_D0, false);
+       if (error)
+               return error;
+
+       if (pci_is_bridge(dev)) {
+               if (prev_state > PCI_D1)
+                       mdelay(PCI_PM_BUS_WAIT);
+       } else {
+               switch(prev_state) {
+               case PCI_D3cold:
+               case PCI_D3hot:
+                       mdelay(pci_pm_d3_delay);
+                       break;
+               case PCI_D2:
+                       udelay(PCI_PM_D2_DELAY);
+                       break;
+               }
+       }
+
+       dev->current_state = PCI_D0;
+
+       return 0;
+}
+
 /**
  * pci_enable_ari - enable ARI forwarding if hardware support it
  * @dev: the PCI device