regulator: core: Consistently set mutex_owner when using ww_mutex_lock_slow()
authorDouglas Anderson <dianders@chromium.org>
Wed, 29 Mar 2023 21:33:53 +0000 (14:33 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 11 May 2023 14:03:13 +0000 (23:03 +0900)
[ Upstream commit b83a1772be854f87602de14726737d3e5b06e1f4 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/regulator/core.c

index 075b850..da929be 100644 (file)
@@ -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,
@@ -6042,6 +6043,7 @@ 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,