From 98a727a4db5162f20aabff15fe04e66255c5cf85 Mon Sep 17 00:00:00 2001 From: Kamil Konieczny Date: Wed, 7 Aug 2019 15:38:35 +0200 Subject: [PATCH] PM / devfreq: exynos-bus: Correct clock enable sequence [ Upstream commit 2c2b20e0da89c76759ee28c6824413ab2fa3bfc6 ] Regulators should be enabled before clocks to avoid h/w hang. This require change in exynos_bus_probe() to move exynos_bus_parse_of() after exynos_bus_parent_parse_of() and change in error handling. Similar change is needed in exynos_bus_exit() where clock should be disabled before regulators. Signed-off-by: Kamil Konieczny Acked-by: Chanwoo Choi Signed-off-by: MyungJoo Ham Signed-off-by: Sasha Levin --- drivers/devfreq/exynos-bus.c | 31 +++++++++++++++++-------------- 1 file changed, 17 insertions(+), 14 deletions(-) diff --git a/drivers/devfreq/exynos-bus.c b/drivers/devfreq/exynos-bus.c index 49f68929e024..25ff31eb1044 100644 --- a/drivers/devfreq/exynos-bus.c +++ b/drivers/devfreq/exynos-bus.c @@ -194,11 +194,10 @@ static void exynos_bus_exit(struct device *dev) if (ret < 0) dev_warn(dev, "failed to disable the devfreq-event devices\n"); - if (bus->regulator) - regulator_disable(bus->regulator); - dev_pm_opp_of_remove_table(dev); clk_disable_unprepare(bus->clk); + if (bus->regulator) + regulator_disable(bus->regulator); } /* @@ -386,6 +385,7 @@ static int exynos_bus_probe(struct platform_device *pdev) struct exynos_bus *bus; int ret, max_state; unsigned long min_freq, max_freq; + bool passive = false; if (!np) { dev_err(dev, "failed to find devicetree node\n"); @@ -399,27 +399,27 @@ static int exynos_bus_probe(struct platform_device *pdev) bus->dev = &pdev->dev; platform_set_drvdata(pdev, bus); - /* Parse the device-tree to get the resource information */ - ret = exynos_bus_parse_of(np, bus); - if (ret < 0) - return ret; - profile = devm_kzalloc(dev, sizeof(*profile), GFP_KERNEL); - if (!profile) { - ret = -ENOMEM; - goto err; - } + if (!profile) + return -ENOMEM; node = of_parse_phandle(dev->of_node, "devfreq", 0); if (node) { of_node_put(node); - goto passive; + passive = true; } else { ret = exynos_bus_parent_parse_of(np, bus); + if (ret < 0) + return ret; } + /* Parse the device-tree to get the resource information */ + ret = exynos_bus_parse_of(np, bus); if (ret < 0) - goto err; + goto err_reg; + + if (passive) + goto passive; /* Initialize the struct profile and governor data for parent device */ profile->polling_ms = 50; @@ -509,6 +509,9 @@ out: err: dev_pm_opp_of_remove_table(dev); clk_disable_unprepare(bus->clk); +err_reg: + if (!passive) + regulator_disable(bus->regulator); return ret; } -- 2.20.1