2023-05-25 11:33:54

by Geert Uytterhoeven

Subject: [PATCH v3 2/2] regulator: core: Streamline debugfs operations

If CONFIG_DEBUG_FS is not set:

regulator: Failed to create debugfs directory
...
regulator-dummy: Failed to create debugfs directory

As per the comments for debugfs_create_dir(), errors returned by this
function should be expected, and ignored:

* If debugfs is not enabled in the kernel, the value -%ENODEV will be
* returned.
*
* NOTE: it's expected that most callers should _ignore_ the errors returned
* by this function. Other debugfs functions handle the fact that the "dentry"
* passed to them could be an error and they don't crash in that case.
* Drivers should generally work fine even if debugfs fails to init anyway.

Adhere to the debugfs spirit, and streamline all operations by:
1. Demoting the importance of the printed error messages to debug
level, like is already done in create_regulator(),
2. Further ignoring any returned errors, as by design, all debugfs
functions are no-ops when passed an error pointer.

Fixes: 2bf1c45be3b8f3a3 ("regulator: Fix error checking for debugfs_create_dir")
Signed-off-by: Geert Uytterhoeven <[email protected]>
---
v3:
- Rebase,

v2:
- Spin off error check fix into a separate patch,
- Improve rationale.
---
drivers/regulator/core.c | 30 +++++++++++++-----------------
1 file changed, 13 insertions(+), 17 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index c1bc4729301d5fed..d8e1caaf207e108f 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1911,19 +1911,17 @@ static struct regulator *create_regulator(struct regulator_dev *rdev,

if (err != -EEXIST)
regulator->debugfs = debugfs_create_dir(supply_name, rdev->debugfs);
- if (IS_ERR(regulator->debugfs)) {
+ if (IS_ERR(regulator->debugfs))
rdev_dbg(rdev, "Failed to create debugfs directory\n");
- } else {
- 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);
- }
+
+ 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
@@ -5256,10 +5254,8 @@ static void rdev_init_debugfs(struct regulator_dev *rdev)
}

rdev->debugfs = debugfs_create_dir(rname, debugfs_root);
- if (IS_ERR(rdev->debugfs)) {
- rdev_warn(rdev, "Failed to create debugfs directory\n");
- return;
- }
+ if (IS_ERR(rdev->debugfs))
+ rdev_dbg(rdev, "Failed to create debugfs directory\n");

debugfs_create_u32("use_count", 0444, rdev->debugfs,
&rdev->use_count);
@@ -6179,7 +6175,7 @@ static int __init regulator_init(void)

debugfs_root = debugfs_create_dir("regulator", NULL);
if (IS_ERR(debugfs_root))
- pr_warn("regulator: Failed to create debugfs directory\n");
+ pr_debug("regulator: Failed to create debugfs directory\n");

#ifdef CONFIG_DEBUG_FS
debugfs_create_file("supply_map", 0444, debugfs_root, NULL,
--
2.34.1