diff mbox series

[v3,09/17] PCI: Generalize pci_bus_max_d3cold_delay to pci_bus_max_delay

Message ID 20200303132852.13184-10-stanspas@amazon.com
State New
Headers show
Series Improve PCI device post-reset readiness polling | expand

Commit Message

Stanislav Spassov March 3, 2020, 1:28 p.m. UTC 
From: Stanislav Spassov <stanspas@amazon.de>

This allows determining the maximum of any of the several delay values
stored in struct pci_dev.

Signed-off-by: Stanislav Spassov <stanspas@amazon.de>
---
 drivers/pci/pci.c | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)
diff mbox series

Patch

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index ba54164652cc..e4840dbf2d1c 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4669,21 +4669,26 @@  bool pcie_wait_for_link(struct pci_dev *pdev, bool active)
 }
 
 /*
- * Find maximum D3cold delay required by all the devices on the bus.  The
- * spec says 100 ms, but firmware can lower it and we allow drivers to
- * increase it as well.
+ * Find maximum delay required by all the devices on the bus after the
+ * given initialization event.
  *
  * Called with @pci_bus_sem locked for reading.
+ *
+ * XXX: It is not clear if this should descend down across bridges (if any)
  */
-static int pci_bus_max_d3cold_delay(const struct pci_bus *bus)
+static int pci_bus_max_delay(const struct pci_bus *bus,
+			     enum pci_init_event event, int default_delay)
 {
 	const struct pci_dev *pdev;
-	int min_delay = 100;
+	int min_delay = default_delay;
 	int max_delay = 0;
 	int delay;
 
+	if (event >= PCI_INIT_EVENT_COUNT)
+		return default_delay;
+
 	list_for_each_entry(pdev, &bus->devices, bus_list) {
-		delay = pdev->delay[PCI_INIT_EVENT_RESET];
+		delay = pdev->delay[event];
 		if (delay < min_delay)
 			min_delay = delay;
 		if (delay > max_delay)
@@ -4728,11 +4733,13 @@  void pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, bool sx_resume)
 		return;
 	}
 
-	/* Take d3cold_delay requirements into account */
+	/* Take delay requirements into account */
 	if (sx_resume && dev->ignore_reset_delay_on_sx_resume)
 		delay = 0;
 	else
-		delay = pci_bus_max_d3cold_delay(dev->subordinate);
+		delay = pci_bus_max_delay(dev->subordinate,
+					  PCI_INIT_EVENT_RESET,
+					  PCI_RESET_DELAY);
 
 	if (!delay) {
 		up_read(&pci_bus_sem);