Re: ehci dynamic debug problem

From: Alan Stern <stern@rowland.harvard.edu>
To: Johannes Stezenbach <js@sig21.net>
Cc: Jason Baron <jbaron@redhat.com>, <linux-kernel@vger.kernel.org>,
	<linux-usb@vger.kernel.org>
Subject: Re: ehci dynamic debug problem
Date: Fri, 13 Apr 2012 15:40:52 -0400 (EDT)	[thread overview]
Message-ID: <Pine.LNX.4.44L0.1204131539280.1146-100000@iolanthe.rowland.org> (raw)
In-Reply-To: <20120413190311.GA6238@sig21.net>

On Fri, 13 Apr 2012, Johannes Stezenbach wrote:

> > > Does it make sense now?
> > 
> > No.  What happens if dynamic debug is enabled for one line that calls 
> > dbg_port_buf() but not for another?  There's no way to avoid the string 
> > formatting in both lines, even though one of them discards the result.
> 
> That's why I said in my initial mail:
> 
>   Does dynamic debug offer an "is the message two lines below enabled" test?
> 
> What I meant is that dbg_port() could test if it
> needs to call dbg_port_buf() for this call site.

Oh.  As far as I know, that's not possible.

> Anyway, maybe the dbg_*_buf() are not called often enough to worry?

Probably not.

> If you're OK with "#if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)"
> then maybe you should just do that?

Yes, that sounds best.

Alan Stern