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Subject: Re: [Bluez PATCH] doc: Add definition for Set Kernel Debug Level
From:   Marcel Holtmann <marcel@holtmann.org>
In-Reply-To: <D61B5AA9-A509-4253-95D7-F6401C832081@holtmann.org>
Date:   Mon, 27 Jan 2020 17:54:46 +0100
Cc:     Johan Hedberg <johan.hedberg@gmail.com>,
        Alain Michaud <alainm@chromium.org>,
        BlueZ <linux-bluetooth@vger.kernel.org>
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To:     Alain Michaud <alainmichaud@google.com>
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Hi Alain,

>> From a high level, this looks good for me although I agree, this is an
>> order of magnitude bigger in terms of scope.  Can you suggest perhaps
>> an interactive way to deliver this over a period of time, perhaps
>> prioritizing the BT_DEBUG kernel messages first? :)
> 
> I am always in favor of increasing the ability to debug things, but we need to do this in a clean fashion and not some short term hacks (since they will come back and haunt us). I like to get some review on my idea first.
> 
> What we could do is work on the BT_DBG etc infrastructure to allow switching when dynamic_debug is not available. Then you would use some debugfs toggle in /sys/kernel/debug/bluetooth since that is no stable API for us (and of course the clear understanding that this toggle is temporary).

I just posted a patch to allow a short term solution. It is similar to the patch you pointed me to with the difference that it is a debugfs entry and limited to the case when dynamic debug is disabled. Is this something that would work until we get a more complete solution worked out and tested?

Regards

Marcel