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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: <CALWDO_Vqboxt4JfV9yGVd5Jv5jZ-vwtOghh4tffpQpQzHuq6NQ@mail.gmail.com>
Date:   Thu, 23 Jan 2020 19:16:56 +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).

Regards

Marcel