Merge branch 'pci/pm'

- Cache the PTM capability offset instead of searching for it every time
  (Bjorn Helgaas)

- Separate PTM configuration from PTM enable (Bjorn Helgaas)

- Add pci_suspend_ptm() and pci_resume_ptm() to disable and re-enable PTM
  on suspend/resume so some Root Ports can safely enter a lower-power PM
  state (Bjorn Helgaas)

- Disable PTM for all devices during suspend; previously we only did this
  for Root Ports and even then only in certain cases (Bjorn Helgaas)

- Simplify pci_pm_suspend_noirq() (Rajvi Jingar)

- Reduce the delay after transitions to/from D3hot by using usleep_range()
  instead of msleep(), which reduces the typical delay from 19ms to 10ms
  (Sajid Dalvi, Will McVicker)

* pci/pm:
  PCI/PM: Reduce D3hot delay with usleep_range()
  PCI/PM: Simplify pci_pm_suspend_noirq()
  PCI/PM: Always disable PTM for all devices during suspend
  PCI/PTM: Consolidate PTM interface declarations
  PCI/PTM: Reorder functions in logical order
  PCI/PTM: Preserve RsvdP bits in PTM Control register
  PCI/PTM: Move pci_ptm_info() body into its only caller
  PCI/PTM: Add pci_suspend_ptm() and pci_resume_ptm()
  PCI/PTM: Separate configuration and enable
  PCI/PTM: Add pci_upstream_ptm() helper
  PCI/PTM: Cache PTM Capability offset

1 files changed, 11 insertions, 33 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 68a49fbaabde..2127aba3550b 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -66,13 +66,15 @@ struct pci_pme_device {
 
 static void pci_dev_d3_sleep(struct pci_dev *dev)
 {
-	unsigned int delay = dev->d3hot_delay;
-
-	if (delay < pci_pm_d3hot_delay)
-		delay = pci_pm_d3hot_delay;
-
-	if (delay)
-		msleep(delay);
+	unsigned int delay_ms = max(dev->d3hot_delay, pci_pm_d3hot_delay);
+	unsigned int upper;
+
+	if (delay_ms) {
+		/* Use a 20% upper bound, 1ms minimum */
+		upper = max(DIV_ROUND_CLOSEST(delay_ms, 5), 1U);
+		usleep_range(delay_ms * USEC_PER_MSEC,
+			     (delay_ms + upper) * USEC_PER_MSEC);
+	}
 }
 
 bool pci_reset_supported(struct pci_dev *dev)
@@ -2708,24 +2710,12 @@ int pci_prepare_to_sleep(struct pci_dev *dev)
 	if (target_state == PCI_POWER_ERROR)
 		return -EIO;
 
-	/*
-	 * There are systems (for example, Intel mobile chips since Coffee
-	 * Lake) where the power drawn while suspended can be significantly
-	 * reduced by disabling PTM on PCIe root ports as this allows the
-	 * port to enter a lower-power PM state and the SoC to reach a
-	 * lower-power idle state as a whole.
-	 */
-	if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT)
-		pci_disable_ptm(dev);
-
 	pci_enable_wake(dev, target_state, wakeup);
 
 	error = pci_set_power_state(dev, target_state);
 
-	if (error) {
+	if (error)
 		pci_enable_wake(dev, target_state, false);
-		pci_restore_ptm_state(dev);
-	}
 
 	return error;
 }
@@ -2766,24 +2756,12 @@ int pci_finish_runtime_suspend(struct pci_dev *dev)
 	if (target_state == PCI_POWER_ERROR)
 		return -EIO;
 
-	/*
-	 * There are systems (for example, Intel mobile chips since Coffee
-	 * Lake) where the power drawn while suspended can be significantly
-	 * reduced by disabling PTM on PCIe root ports as this allows the
-	 * port to enter a lower-power PM state and the SoC to reach a
-	 * lower-power idle state as a whole.
-	 */
-	if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT)
-		pci_disable_ptm(dev);
-
 	__pci_enable_wake(dev, target_state, pci_dev_run_wake(dev));
 
 	error = pci_set_power_state(dev, target_state);
 
-	if (error) {
+	if (error)
 		pci_enable_wake(dev, target_state, false);
-		pci_restore_ptm_state(dev);
-	}
 
 	return error;
 }