[RFC PATCH v2 0/4] staging: vc04: Drop custom logging

Stefan Wahren stefan.wahren at i2se.com
Sun Sep 17 08:36:13 PDT 2023


Hi,

Am 14.09.23 um 08:35 schrieb Dan Carpenter:
> On Thu, Sep 14, 2023 at 12:25:24AM +0530, Umang Jain wrote:
>> Hello,
>>
>> This series attempts to restart the discussion on custom logging used
>> in VC04. In the last feedback gathered in [1] it seems that the logging
>> would rather be moved to use dynamic debug. The series tries to move
>> in that direction.
>>
>> The elephant in the room is the ability of turning on/off log levels,
>> which this series just drops. Compensated by a crude strings
>> ("error", "warning", "info"... etc) for easier grepping.
>>
>> The log category are also just strings (which probably can be transformed
>> to dynamic debug class names moving forwards?).
>>
>> To move forwards, I would like feedback on the broader direction.
>> There are couple of TODOs in each of the patch (summarised in commit
>> messages) which require case-by-case discussion.
>>
>> Additional high-level questions to move forwards:
>> 1. Is loss of log levels by moving to dynamic debug, is actually a
>>     concern? Is dynamic debug a valid replacement?
> 
> Dynamic debug is honestly going to be an improvement.  I guess, Greg and
> I said this back in Jan.
> 
>> 2. Whether debugfs should be dropped as well, found vestigial in [2]
> 
> Yes. The "vchiq/log" should be removed.  Ideally as part of this
> patchset so it's easier to understand.

Yes, but please do not remote vchiq_debugfs entirely. I'm working on a 
patch to move the state dump (debug feature) from the character device 
/dev/vchiq to debugfs /sys/kernel/debug/vchiq/dump_state.

> 
>> 3. whether vchiq_log_trace() should actually be tracing support for VC04
> 
> That can be done later if people want.  No need to discuss it now.
> 
> regards,
> dan carpenter
> 



More information about the linux-arm-kernel mailing list