linux-kernel - [PATCH] regulator: core: fix debugfs creation regression

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Message-ID: <20240509133304.8883-1-johan+linaro@kernel.org>
Date: Thu,  9 May 2024 15:33:04 +0200
From: Johan Hovold <johan+linaro@...nel.org>
To: Mark Brown <broonie@...nel.org>
Cc: Liam Girdwood <lgirdwood@...il.com>,
	linux-kernel@...r.kernel.org,
	Johan Hovold <johan+linaro@...nel.org>,
	stable@...r.kernel.org,
	Geert Uytterhoeven <geert+renesas@...der.be>
Subject: [PATCH] regulator: core: fix debugfs creation regression

regulator_get() may sometimes be called more than once for the same
consumer device, something which before commit dbe954d8f163 ("regulator:
core: Avoid debugfs: Directory ...  already present! error") resulted in
errors being logged.

A couple of recent commits broke the handling of such cases so that
attributes are now erroneously created in the debugfs root directory the
second time a regulator is requested and the log is filled with errors
like:

	debugfs: File 'uA_load' in directory '/' already present!
	debugfs: File 'min_uV' in directory '/' already present!
	debugfs: File 'max_uV' in directory '/' already present!
	debugfs: File 'constraint_flags' in directory '/' already present!

on any further calls.

Fixes: 2715bb11cfff ("regulator: core: Fix more error checking for debugfs_create_dir()")
Fixes: 08880713ceec ("regulator: core: Streamline debugfs operations")
Cc: stable@...r.kernel.org
Cc: Geert Uytterhoeven <geert+renesas@...der.be>
Signed-off-by: Johan Hovold <johan+linaro@...nel.org>
---
 drivers/regulator/core.c | 27 ++++++++++++++++-----------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index dabac9772741..2c33653ffdea 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1911,19 +1911,24 @@ static struct regulator *create_regulator(struct regulator_dev *rdev,
 		}
 	}
 
-	if (err != -EEXIST)
+	if (err != -EEXIST) {
 		regulator->debugfs = debugfs_create_dir(supply_name, rdev->debugfs);
-	if (IS_ERR(regulator->debugfs))
-		rdev_dbg(rdev, "Failed to create debugfs directory\n");
+		if (IS_ERR(regulator->debugfs)) {
+			rdev_dbg(rdev, "Failed to create debugfs directory\n");
+			regulator->debugfs = NULL;
+		}
+	}
 
-	debugfs_create_u32("uA_load", 0444, regulator->debugfs,
-			   &regulator->uA_load);
-	debugfs_create_u32("min_uV", 0444, regulator->debugfs,
-			   &regulator->voltage[PM_SUSPEND_ON].min_uV);
-	debugfs_create_u32("max_uV", 0444, regulator->debugfs,
-			   &regulator->voltage[PM_SUSPEND_ON].max_uV);
-	debugfs_create_file("constraint_flags", 0444, regulator->debugfs,
-			    regulator, &constraint_flags_fops);
+	if (regulator->debugfs) {
+		debugfs_create_u32("uA_load", 0444, regulator->debugfs,
+				   &regulator->uA_load);
+		debugfs_create_u32("min_uV", 0444, regulator->debugfs,
+				   &regulator->voltage[PM_SUSPEND_ON].min_uV);
+		debugfs_create_u32("max_uV", 0444, regulator->debugfs,
+				   &regulator->voltage[PM_SUSPEND_ON].max_uV);
+		debugfs_create_file("constraint_flags", 0444, regulator->debugfs,
+				    regulator, &constraint_flags_fops);
+	}
 
 	/*
 	 * Check now if the regulator is an always on regulator - if
-- 
2.43.2