linux-kernel - Re: Regression found (Stop-marking-clocks-as-CLK_IS

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Date:   Fri, 25 Jan 2019 22:30:58 +0200
From:   Andy Shevchenko <andy.shevchenko@...il.com>
To:     Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>
Cc:     Mogens Jensen <mogens-jensen@...tonmail.com>,
        Hans de Goede <hdegoede@...hat.com>,
        Dean Wallace <duffydack73@...il.com>,
        Stephen Boyd <sboyd@...nel.org>,
        Michael Turquette <mturquette@...libre.com>,
        linux-clk <linux-clk@...r.kernel.org>,
        Stable <stable@...r.kernel.org>,
        Johannes Stezenbach <js@...21.net>,
        Carlo Caione <carlo@...lessm.com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: Regression found (Stop-marking-clocks-as-CLK_IS_CRITICAL)

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 — nothing should be printed at all
- otherwise if CONFIG_DYNAMIC_DEBUG — 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