From b83a1772be854f87602de14726737d3e5b06e1f4 Mon Sep 17 00:00:00 2001
From: Douglas Anderson <dianders@chromium.org>
Date: Wed, 29 Mar 2023 14:33:53 -0700
Subject: [PATCH] regulator: core: Consistently set mutex_owner when using ww_mutex_lock_slow()
Git-commit: b83a1772be854f87602de14726737d3e5b06e1f4
Patch-mainline: v6.4-rc1
References: git-fixes

When a codepath locks a rdev using ww_mutex_lock_slow() directly then
that codepath is responsible for incrementing the "ref_cnt" and also
setting the "mutex_owner" to "current".

The regulator core consistently got that right for "ref_cnt" but
didn't always get it right for "mutex_owner". Let's fix this.

It's unlikely that this truly matters because the "mutex_owner" is
only needed if we're going to do subsequent locking of the same
rdev. However, even though it's not truly needed it seems less
surprising if we consistently set "mutex_owner" properly.

Fixes: f8702f9e4aa7 ("regulator: core: Use ww_mutex for regulators locking")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20230329143317.RFC.v2.1.I4e9d433ea26360c06dd1381d091c82bb1a4ce843@changeid
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/regulator/core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 1490eb40c973..9a13240f3084 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -334,6 +334,7 @@ static void regulator_lock_dependent(struct regulator_dev *rdev,
 			ww_mutex_lock_slow(&new_contended_rdev->mutex, ww_ctx);
 			old_contended_rdev = new_contended_rdev;
 			old_contended_rdev->ref_cnt++;
+			old_contended_rdev->mutex_owner = current;
 		}
 
 		err = regulator_lock_recursive(rdev,
@@ -6048,6 +6049,7 @@ static void regulator_summary_lock(struct ww_acquire_ctx *ww_ctx)
 			ww_mutex_lock_slow(&new_contended_rdev->mutex, ww_ctx);
 			old_contended_rdev = new_contended_rdev;
 			old_contended_rdev->ref_cnt++;
+			old_contended_rdev->mutex_owner = current;
 		}
 
 		err = regulator_summary_lock_all(ww_ctx,
-- 
2.35.3