[PATCH v6 8/9] PCI: brcmstb: Do not turn off regulators if EP can wake up
From: Jim Quinlan <jim2101024@gmail.com>
Date: 2021-10-29 20:04:19
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 may wake up during S2/S3 suspend, we do not want to turn off its power when suspending. Signed-off-by: Jim Quinlan <jim2101024@gmail.com> --- drivers/pci/controller/pcie-brcmstb.c | 49 ++++++++++++++++++++++++--- 1 file changed, 45 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index 6635e143cfcb..18b9f7c97864 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c@@ -192,6 +192,7 @@ static inline void brcm_pcie_bridge_sw_init_set_generic(struct brcm_pcie *pcie, static inline void brcm_pcie_perst_set_4908(struct brcm_pcie *pcie, u32 val); static inline void brcm_pcie_perst_set_7278(struct brcm_pcie *pcie, u32 val); static inline void brcm_pcie_perst_set_generic(struct brcm_pcie *pcie, u32 val); +static bool brcm_pcie_link_up(struct brcm_pcie *pcie); static const char * const supplies[] = { "vpcie3v3",
@@ -304,8 +305,20 @@ struct brcm_pcie { void (*bridge_sw_init_set)(struct brcm_pcie *pcie, u32 val); struct regulator_bulk_data supplies[ARRAY_SIZE(supplies)]; unsigned int num_supplies; + bool ep_wakeup_capable; }; +static int pci_dev_may_wakeup(struct pci_dev *dev, void *data) +{ + bool *ret = data; + + if (device_may_wakeup(&dev->dev)) { + *ret = true; + dev_dbg(&dev->dev, "disable cancelled for wake-up device\n"); + } + return (int) *ret; +} + static int brcm_regulators_on(struct brcm_pcie *pcie) { struct device *dev = pcie->dev;
@@ -313,6 +326,18 @@ static int brcm_regulators_on(struct brcm_pcie *pcie) if (!pcie->num_supplies) return 0; + + if (pcie->ep_wakeup_capable) { + /* + * We are resuming from a suspend. In the previous 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; + return 0; + } + ret = regulator_bulk_enable(pcie->num_supplies, pcie->supplies); if (ret) dev_err(dev, "failed to enable EP regulators\n");
@@ -320,13 +345,28 @@ static int brcm_regulators_on(struct brcm_pcie *pcie) return ret; } -static int brcm_regulators_off(struct brcm_pcie *pcie) +static int brcm_regulators_off(struct brcm_pcie *pcie, bool force) { + struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie); struct device *dev = pcie->dev; int ret; if (!pcie->num_supplies) return 0; + + pcie->ep_wakeup_capable = false; + + if (!force && bridge->bus && brcm_pcie_link_up(pcie)) { + /* + * If at least one device on this bus is enabled as a + * wake-up source, do not turn off regulators. + */ + pci_walk_bus(bridge->bus, pci_dev_may_wakeup, + &pcie->ep_wakeup_capable); + if (pcie->ep_wakeup_capable) + return 0; + } + ret = regulator_bulk_disable(pcie->num_supplies, pcie->supplies); if (ret) dev_err(dev, "failed to disable EP regulators\n");
@@ -1248,7 +1288,7 @@ static int brcm_pcie_suspend(struct device *dev) reset_control_rearm(pcie->rescal); clk_disable_unprepare(pcie->clk); - return brcm_regulators_off(pcie); + return brcm_regulators_off(pcie, false); } static int brcm_pcie_resume(struct device *dev)
@@ -1264,6 +1304,7 @@ static int brcm_pcie_resume(struct device *dev) ret = reset_control_reset(pcie->rescal); if (ret) goto err_disable_clk; + ret = brcm_regulators_on(pcie); if (ret) goto err_reset;
@@ -1311,7 +1352,7 @@ static void __brcm_pcie_remove(struct brcm_pcie *pcie) reset_control_rearm(pcie->rescal); clk_disable_unprepare(pcie->clk); if (pcie->num_supplies) { - brcm_regulators_off(pcie); + brcm_regulators_off(pcie, true); regulator_bulk_free(pcie->num_supplies, pcie->supplies); } }
@@ -1382,7 +1423,7 @@ static int brcm_pcie_pci_subdev_prepare(struct pci_bus *bus, int devfn, return 0; err_out1: - brcm_regulators_off(pcie); + brcm_regulators_off(pcie, true); err_out0: regulator_bulk_free(pcie->num_supplies, pcie->supplies); pcie->num_supplies = 0;
--
2.17.1
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