[PATCH] drm/exynos: hdmi: don't leak enable HDMI_EN regulator if probe fails

[Marek Szyprowski]

Move enabling and disabling HDMI_EN optional regulator to probe() function
to keep track on the regulator status. This fixes following warning if
probe() fails (for example when I2C DDC adapter cannot be yet gathered
due to the missing driver). This fixes following warning observed on
Arndale5250 board with multi_v7_defconfig:

[drm] Failed to get ddc i2c adapter by node
------------[ cut here ]------------
WARNING: CPU: 0 PID: 214 at drivers/regulator/core.c:2051 _regulator_put+0x16c/0x184
Modules linked in: ...
CPU: 0 PID: 214 Comm: systemd-udevd Not tainted 5.6.0-rc2-next-20200219-00040-g38af1dfafdbb #7570
Hardware name: Samsung Exynos (Flattened Device Tree)
[<c0312258>] (unwind_backtrace) from [<c030cc10>] (show_stack+0x10/0x14)
[<c030cc10>] (show_stack) from [<c0f0d3a0>] (dump_stack+0xcc/0xe0)
[<c0f0d3a0>] (dump_stack) from [<c0346a58>] (__warn+0xe0/0xf8)
[<c0346a58>] (__warn) from [<c0346b20>] (warn_slowpath_fmt+0xb0/0xb8)
[<c0346b20>] (warn_slowpath_fmt) from [<c0893f58>] (_regulator_put+0x16c/0x184)
[<c0893f58>] (_regulator_put) from [<c0893f8c>] (regulator_put+0x1c/0x2c)
[<c0893f8c>] (regulator_put) from [<c09b2664>] (release_nodes+0x17c/0x200)
[<c09b2664>] (release_nodes) from [<c09aebe8>] (really_probe+0x10c/0x350)
[<c09aebe8>] (really_probe) from [<c09aefa8>] (driver_probe_device+0x60/0x1a0)
[<c09aefa8>] (driver_probe_device) from [<c09af288>] (device_driver_attach+0x58/0x60)
[<c09af288>] (device_driver_attach) from [<c09af310>] (__driver_attach+0x80/0xbc)
[<c09af310>] (__driver_attach) from [<c09ace34>] (bus_for_each_dev+0x68/0xb4)
[<c09ace34>] (bus_for_each_dev) from [<c09ae00c>] (bus_add_driver+0x130/0x1e8)
[<c09ae00c>] (bus_add_driver) from [<c09afd98>] (driver_register+0x78/0x110)
[<c09afd98>] (driver_register) from [<bf139558>] (exynos_drm_init+0xe8/0x11c [exynosdrm])
[<bf139558>] (exynos_drm_init [exynosdrm]) from [<c0302fa8>] (do_one_initcall+0x50/0x220)
[<c0302fa8>] (do_one_initcall) from [<c03dc02c>] (do_init_module+0x60/0x210)
[<c03dc02c>] (do_init_module) from [<c03daf44>] (load_module+0x1c0c/0x2310)
[<c03daf44>] (load_module) from [<c03db85c>] (sys_finit_module+0xac/0xbc)
[<c03db85c>] (sys_finit_module) from [<c0301000>] (ret_fast_syscall+0x0/0x54)
Exception stack(0xecca3fa8 to 0xecca3ff0)
...
---[ end trace 276c91214635905c ]---

Signed-off-by: Marek Szyprowski <m.szyprowski at samsung.com>
---
 drivers/gpu/drm/exynos/exynos_hdmi.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_hdmi.c b/drivers/gpu/drm/exynos/exynos_hdmi.c
index 9ff921f43a93..f141916eade6 100644
--- a/drivers/gpu/drm/exynos/exynos_hdmi.c
+++ b/drivers/gpu/drm/exynos/exynos_hdmi.c
@@ -1805,18 +1805,10 @@ static int hdmi_resources_init(struct hdmi_context *hdata)
 
 	hdata->reg_hdmi_en = devm_regulator_get_optional(dev, "hdmi-en");
 
-	if (PTR_ERR(hdata->reg_hdmi_en) != -ENODEV) {
+	if (PTR_ERR(hdata->reg_hdmi_en) != -ENODEV)
 		if (IS_ERR(hdata->reg_hdmi_en))
 			return PTR_ERR(hdata->reg_hdmi_en);
 
-		ret = regulator_enable(hdata->reg_hdmi_en);
-		if (ret) {
-			DRM_DEV_ERROR(dev,
-				      "failed to enable hdmi-en regulator\n");
-			return ret;
-		}
-	}
-
 	return hdmi_bridge_init(hdata);
 }
 
@@ -2023,6 +2015,15 @@ static int hdmi_probe(struct platform_device *pdev)
 		}
 	}
 
+	if (!IS_ERR(hdata->reg_hdmi_en)) {
+		ret = regulator_enable(hdata->reg_hdmi_en);
+		if (ret) {
+			DRM_DEV_ERROR(dev,
+			      "failed to enable hdmi-en regulator\n");
+			goto err_hdmiphy;
+		}
+	}
+
 	pm_runtime_enable(dev);
 
 	audio_infoframe = &hdata->audio.infoframe;
@@ -2047,7 +2048,8 @@ static int hdmi_probe(struct platform_device *pdev)
 
 err_rpm_disable:
 	pm_runtime_disable(dev);
-
+	if (!IS_ERR(hdata->reg_hdmi_en))
+		regulator_disable(hdata->reg_hdmi_en);
 err_hdmiphy:
 	if (hdata->hdmiphy_port)
 		put_device(&hdata->hdmiphy_port->dev);
-- 
2.17.1