Re: Regression found (Stop-marking-clocks-as-CLK_IS_CRITICAL)

From: Andy Shevchenko
Date: Fri Jan 25 2019 - 15:31:06 EST


On Fri, Jan 25, 2019 at 11:57:57AM -0600, Pierre-Louis Bossart wrote:
>
> > > > The only minor annoyance I'm experiencing now, is a large amount of debug output from something in kernel log when audio is played on the system:
> > > > writing to lpe: 00000000: 01 01 01 01 00 00 08 00 ff ff ff ff 55 00 00 00 ............U...
> > > > writing to lpe: 00000000: 01 01 01 01 00 00 1a 00 ff ff ff ff 75 00 12 00 ............u...
> > > > ...
> > > That's enabled via dynamic debug so that's rather a configuration issue
> > > than a kernel problem?
> > Do you have any suggestions on how to disable it?
> >
> > My kernel is compiled without DYNAMIC_DEBUG, DEBUG_FS and other debug features, so I don't understand why all this debug output is flooding the kernel log.
> >
> > It's a minor issue, but it would be nice to get rid of it.
> I can confirm that this happens without DYNAMIC_DEBUG, and somehow changing
> the log level doesn't seem to matter. I tried changing the console log as a
> kernel parameter or with playing /proc/sys/kernel/printk, no luck. weird.

Are you sure you did a clean build?

The logic behind print_hex_dump_bytes() is following:
- if !CONFIG_PRINTK â nothing should be printed at all
- otherwise if CONFIG_DYNAMIC_DEBUG â it goes thru its facilities
- else if goes to KERN_DEBUG level and thus loglevel should affect this either
thru command line or via procfs

If none of the above works like it should, the couple of possibilities I can see:
- unclean build where previously it was compiled somehow with DEBUG
- ignore_loglevel is in the kernel command line

--
With Best Regards,
Andy Shevchenko