On 2/5/24 23:33, Krzysztof Kozlowski wrote:
On 05/02/2024 17:15, Guenter Roeck wrote:
On Mon, Feb 05, 2024 at 04:26:08PM +0100, Krzysztof Kozlowski wrote:
On 05/02/2024 16:20, Cosmo Chou wrote:
This driver implements support for temperature monitoring of Astera Labs
PT5161L series PCIe retimer chips.
This driver implementation originates from the CSDK available at
Link: https://github.com/facebook/openbmc/tree/helium/common/recipes-lib/retimer-v2.14
The communication protocol utilized is based on the I2C/SMBus standard.
Signed-off-by: Cosmo Chou <chou.cosmo@xxxxxxxxx>
---
[ ... ]
+
+static int __init pt5161l_init(void)
+{
+ pt5161l_debugfs_dir = debugfs_create_dir("pt5161l", NULL);
Drivers don't need initcalls. For sure any debugfs should not be handled
here but in probe.
Lots of hwmon drivers have init functions, for basic chip detection of
Super-I/O chips (example: drivers/hwmon/nct6775-platform.c) and to create
a parent debugfs subdirectory for the driver. The probe function then adds
subdirecties per chip instantiation. Example for pmbus, in
drivers/hwmon/pmbus/pmbus_core.c:
Core bus components are a bit different...
static int __init pmbus_core_init(void)
{
pmbus_debugfs_dir = debugfs_create_dir("pmbus", NULL);
if (IS_ERR(pmbus_debugfs_dir))
pmbus_debugfs_dir = NULL;
return 0;
}
static void __exit pmbus_core_exit(void)
{
debugfs_remove_recursive(pmbus_debugfs_dir);
}
Are you saying this is all wrong ? What alternative would you suggest ?
Just create parent directory in probe and only keep remove in __exit.
But you are right that might not be much better approach.
That would just add more code and increase complexity since it would require
a mutex to protect against parallel probes. On the plus side, it would only
create the driver root directory if necessary, that is, if there is an
actual device. I am not sure if that would be worth the increased complexity.
That makes me wonder, though, if an API function such as
struct dentry *hwmon_debugfs_get_root(char *name);
would make sense. That would move the complexity to the hwmon core and
unify its handling. I'll think about that. For the time being, I'll
accept the code as-is.
Thanks,
Guenter
