Thread (13 messages) flat view 13 messages, 5 authors, 2022-01-04
STALE1675d

Revision v10 of 3 in this series.

Revisions (3)
  1. v9 [diff vs current]
  2. v10 current
  3. v11 [diff vs current]

[PATCH v10 7/7] PCI: brcmstb: Do not turn off WOL regulators on suspend

From: Jim Quinlan <jim2101024@gmail.com>
Date: 2021-12-09 21:14:44
Also in: linux-pci, lkml
Subsystem: broadcom bcm2711/bcm2835 arm architecture, broadcom bcm7xxx arm architecture, broadcom stb pcie driver, pci native host bridge and endpoint drivers, pci subsystem, the rest · Maintainers: Florian Fainelli, Jim Quinlan, Lorenzo Pieralisi, Krzysztof Wilczyński, Manivannan Sadhasivam, Bjorn Helgaas, Linus Torvalds

If any downstream device can be awoken do not turn off
the regulators as the device will need them on.

Signed-off-by: Jim Quinlan <jim2101024@gmail.com>
---
 drivers/pci/controller/pcie-brcmstb.c | 53 ++++++++++++++++++++++-----
 1 file changed, 44 insertions(+), 9 deletions(-)
diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index 9b4df253e79a..8e5cbf6850cd 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -298,6 +298,7 @@ struct brcm_pcie {
 	void			(*bridge_sw_init_set)(struct brcm_pcie *pcie, u32 val);
 	bool			refusal_mode;
 	struct subdev_regulators *sr;
+	bool			ep_wakeup_capable;
 };
 
 /*
@@ -1166,9 +1167,21 @@ static void brcm_pcie_turn_off(struct brcm_pcie *pcie)
 	pcie->bridge_sw_init_set(pcie, 1);
 }
 
+static int pci_dev_may_wakeup(struct pci_dev *dev, void *data)
+{
+	bool *ret = data;
+
+	if (device_may_wakeup(&dev->dev)) {
+		*ret = true;
+		dev_info(&dev->dev, "disable cancelled for wake-up device\n");
+	}
+	return (int) *ret;
+}
+
 static int brcm_pcie_suspend(struct device *dev)
 {
 	struct brcm_pcie *pcie = dev_get_drvdata(dev);
+	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
 	int ret;
 
 	brcm_pcie_turn_off(pcie);
@@ -1187,11 +1200,22 @@ static int brcm_pcie_suspend(struct device *dev)
 	}
 
 	if (pcie->sr) {
-		ret = regulator_bulk_disable(pcie->sr->num_supplies, pcie->sr->supplies);
-		if (ret) {
-			dev_err(dev, "Could not turn off regulators\n");
-			reset_control_reset(pcie->rescal);
-			return ret;
+		/*
+		 * Now turn off the regulators, but if at least one
+		 * downstream device is enabled as a wake-up source, do not
+		 * turn off regulators.
+		 */
+		pcie->ep_wakeup_capable = false;
+		pci_walk_bus(bridge->bus, pci_dev_may_wakeup,
+			     &pcie->ep_wakeup_capable);
+		if (!pcie->ep_wakeup_capable) {
+			ret = regulator_bulk_disable(pcie->sr->num_supplies,
+						     pcie->sr->supplies);
+			if (ret) {
+				dev_err(dev, "Could not turn off regulators\n");
+				reset_control_reset(pcie->rescal);
+				return ret;
+			}
 		}
 	}
 	clk_disable_unprepare(pcie->clk);
@@ -1212,10 +1236,21 @@ static int brcm_pcie_resume(struct device *dev)
 		return ret;
 
 	if (pcie->sr) {
-		ret = regulator_bulk_enable(pcie->sr->num_supplies, pcie->sr->supplies);
-		if (ret) {
-			dev_err(dev, "Could not turn on regulators\n");
-			goto err_disable_clk;
+		if (pcie->ep_wakeup_capable) {
+			/*
+			 * We are resuming from a suspend.  In the suspend we
+			 * did not disable the power supplies, so there is
+			 * no need to enable them (and falsely increase their
+			 * usage count).
+			 */
+			pcie->ep_wakeup_capable = false;
+		} else {
+			ret = regulator_bulk_enable(pcie->sr->num_supplies,
+						    pcie->sr->supplies);
+			if (ret) {
+				dev_err(dev, "Could not turn on regulators\n");
+				goto err_disable_clk;
+			}
 		}
 	}
 
-- 
2.17.1


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