On 1/25/25 10:24, Guenter Roeck wrote:
On 1/23/25 08:33, Wolfram Sang wrote:
The I2C core now manages a debugfs dir per i2c_client. PMBus has its own
debugfs hierarchy. Link the two, so a user will be pointed to the pmbus
domain from the i2c domain.
Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
---
@Guenter: I don't have any PMBus device here. Would you be interested to
test this patch? It build tests fine at least.
drivers/hwmon/pmbus/pmbus_core.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 787683e83db6..510b88aed326 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -3517,6 +3517,7 @@ static int pmbus_init_debugfs(struct i2c_client *client,
int i, idx = 0;
char name[PMBUS_NAME_SIZE];
struct pmbus_debugfs_entry *entries;
+ const char *symlink, *hwmon_name = dev_name(data->hwmon_dev);
if (!pmbus_debugfs_dir)
return -ENODEV;
@@ -3525,13 +3526,19 @@ static int pmbus_init_debugfs(struct i2c_client *client,
* Create the debugfs directory for this device. Use the hwmon device
* name to avoid conflicts (hwmon numbers are globally unique).
*/
- data->debugfs = debugfs_create_dir(dev_name(data->hwmon_dev),
- pmbus_debugfs_dir);
+ data->debugfs = debugfs_create_dir(hwmon_name, pmbus_debugfs_dir);
if (IS_ERR_OR_NULL(data->debugfs)) {
data->debugfs = NULL;
return -ENODEV;
}
+ /* The default i2c_client debugfs dir should link to where the data is */
+ symlink = kasprintf(GFP_KERNEL, "../../pmbus/%s", hwmon_name);
This would have to be "../../../pmbus/".
+ if (!symlink)
+ return -ENOMEM;
+ debugfs_create_symlink(hwmon_name, client->debugfs, symlink);
As mentioned separately, the symlink is not removed if a driver is unloaded.
When it is loaded again, dmesg says something like
debugfs: File 'hwmon9' in directory '3-0020' already present!
Also, the symlink ends up in, for example,
/sys/kernel/debug/i2c/i2c-3/3-0020
and looks like
hwmon9 -> ../../../pmbus/hwmon9
meaning there is an unnecessary "hwmon9" subdirectory in
/sys/kernel/debug/i2c/i2c-3/3-0020
I would prefer to have the actual debugfs files in the i2c debugfs directory
(here /sys/kernel/debug/i2c/i2c-3/3-0020) and create a symlink from
/sys/kernel/debug/pmbus/, such as
/sys/kernel/debug/pmbus/hwmon9 -> ../i2c/i2c-3/3-0020
I tried to implement it, but right now that doesn't work because the
actual debugfs files are not removed from i2c/i2c-3/3-0020 if a driver
is unloaded and I don't immediately see how to fix that.
I was able to implement this after fixing the problem in the i2c code.
It works quite nicely.
root@server:/sys/kernel/debug/pmbus# ls -l
total 0
lrwxrwxrwx 1 root root 0 Jan 25 12:07 hwmon9 -> ../i2c/i2c-5/5-0020
root@server:/sys/kernel/debug/pmbus# cd ../i2c/i2c-5/5-0020
root@server:/sys/kernel/debug/i2c/i2c-5/5-0020# ls
mfr_id mfr_model mfr_revision status0 status0_input status0_iout status0_mfr
Guenter
