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

[Stefan Wahren]

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