Re: [PATCH v4 0/3] hwmon: (pmbus/adm1266) add clear_blackbox and powerup_counter debugfs entries

["Abdurrahman Hussain" <abdurrahman@nexthop.ai>]

On Wed May 20, 2026 at 7:10 AM PDT, Guenter Roeck wrote:
> Hi,
>
> On 5/16/26 18:18, Abdurrahman Hussain wrote:
>> This is what remains of the v3 series after Guenter applied patches
>> 1/5 (firmware_revision) and 5/5 (GPIO line label) to hwmon-next, and
>> asked for patch 4/5 (rtc_class) to be dropped.
>> 
>> Patch 1 adds a write-only clear_blackbox debugfs file. Devices
>> configured for single-recording mode (BLACKBOX_CONFIG[0] = 0) need
>> an explicit clear once the 32-record buffer fills; the documented
>> sub-command ({0xFE, 0x00} block-write to 0xDE) wasn't reachable
>> from userspace. The patch also acquires pmbus_lock at the
>> adm1266_nvmem_read() callback boundary so the memset of
>> data->dev_mem, the blackbox refill, and the memcpy to userspace run
>> as a single critical section -- the nvmem core does not serialize
>> concurrent reg_read calls.
>> 
>> Patch 2 exposes the non-volatile POWERUP_COUNTER (0xE4) via debugfs.
>> The same value is embedded in every blackbox record, so the live
>> value lets userspace match a captured record back to the boot it
>> came from when correlating logs. The block-read is taken under
>> pmbus_lock to serialise against any pmbus_core PAGE+register
>> sequence on the device.
>> 
>> Patch 3 takes pmbus_lock in adm1266_state_read() (the pre-existing
>> sequencer_state debugfs handler) for the same defensive-locking
>> reason that motivates the new debugfs files in patches 1 and 2:
>> any direct device access from outside pmbus_core should be ordered
>> with respect to pmbus_core's own PAGE+register sequences.
>> 
>> Signed-off-by: Abdurrahman Hussain <abdurrahman@nexthop.ai>
>
> The series no longer applies after applying the bug fix series.
> Please rebase it on top of the hwmon-next branch of
> git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git
> and resubmit.
>
> Sorry for the trouble, and thanks a lot for fixing all the problems
> with the driver.
>
> Guenter

Will do, thank you for your support!

Abdurrahman