From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Jon Hunter Date: Mon, 24 Feb 2020 14:07:48 +0000 Subject: [PATCH] backlight: lp855x: Ensure regulators are disabled on probe failure If probing the LP885x backlight fails after the regulators have been enabled, then the following warning is seen when releasing the regulators ... WARNING: CPU: 1 PID: 289 at drivers/regulator/core.c:2051 _regulator_put.part.28+0x158/0x160 Modules linked in: tegra_xudc lp855x_bl(+) host1x pwm_tegra ip_tables x_tables ipv6 nf_defrag_ipv6 CPU: 1 PID: 289 Comm: systemd-udevd Not tainted 5.6.0-rc2-next-20200224 #1 Hardware name: NVIDIA Jetson TX1 Developer Kit (DT) ... Call trace: _regulator_put.part.28+0x158/0x160 regulator_put+0x34/0x50 devm_regulator_release+0x10/0x18 release_nodes+0x12c/0x230 devres_release_all+0x34/0x50 really_probe+0x1c0/0x370 driver_probe_device+0x58/0x100 device_driver_attach+0x6c/0x78 __driver_attach+0xb0/0xf0 bus_for_each_dev+0x68/0xc8 driver_attach+0x20/0x28 bus_add_driver+0x160/0x1f0 driver_register+0x60/0x110 i2c_register_driver+0x40/0x80 lp855x_driver_init+0x20/0x1000 [lp855x_bl] do_one_initcall+0x58/0x1a0 do_init_module+0x54/0x1d0 load_module+0x1d80/0x21c8 __do_sys_finit_module+0xe8/0x100 __arm64_sys_finit_module+0x18/0x20 el0_svc_common.constprop.3+0xb0/0x168 do_el0_svc+0x20/0x98 el0_sync_handler+0xf4/0x1b0 el0_sync+0x140/0x180 Fix this by ensuring that the regulators are disabled, if enabled, on probe failure. Finally, ensure that the vddio regulator is disabled in the driver remove handler. Signed-off-by: Jon Hunter Reviewed-by: Daniel Thompson --- drivers/video/backlight/lp855x_bl.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/drivers/video/backlight/lp855x_bl.c b/drivers/video/backlight/lp855x_bl.c index f68920131a4a..e94932c69f54 100644 --- a/drivers/video/backlight/lp855x_bl.c +++ b/drivers/video/backlight/lp855x_bl.c @@ -456,7 +456,7 @@ static int lp855x_probe(struct i2c_client *cl, const struct i2c_device_id *id) ret = regulator_enable(lp->enable); if (ret < 0) { dev_err(lp->dev, "failed to enable vddio: %d\n", ret); - return ret; + goto disable_supply; } /* @@ -471,24 +471,34 @@ static int lp855x_probe(struct i2c_client *cl, const struct i2c_device_id *id) ret = lp855x_configure(lp); if (ret) { dev_err(lp->dev, "device config err: %d", ret); - return ret; + goto disable_vddio; } ret = lp855x_backlight_register(lp); if (ret) { dev_err(lp->dev, "failed to register backlight. err: %d\n", ret); - return ret; + goto disable_vddio; } ret = sysfs_create_group(&lp->dev->kobj, &lp855x_attr_group); if (ret) { dev_err(lp->dev, "failed to register sysfs. err: %d\n", ret); - return ret; + goto disable_vddio; } backlight_update_status(lp->bl); + return 0; + +disable_vddio: + if (lp->enable) + regulator_disable(lp->enable); +disable_supply: + if (lp->supply) + regulator_disable(lp->supply); + + return ret; } static int lp855x_remove(struct i2c_client *cl) @@ -497,6 +507,8 @@ static int lp855x_remove(struct i2c_client *cl) lp->bl->props.brightness = 0; backlight_update_status(lp->bl); + if (lp->enable) + regulator_disable(lp->enable); if (lp->supply) regulator_disable(lp->supply); sysfs_remove_group(&lp->dev->kobj, &lp855x_attr_group); -- 2.26.2