Messages in this thread | | | Date | Wed, 6 Oct 2004 15:33:10 +0200 | From | Jörn Engel <> | Subject | Re: [PATCH] Console: fall back to /dev/null when no console is availlable |
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On Wed, 6 October 2004 15:07:05 +0200, Geert Uytterhoeven wrote: > On Wed, 6 Oct 2004, [iso-8859-1] Jörn Engel wrote: > > > > Point is that above patch is simpler and empiria didn't give me a > > reason to worry about anything else. > > I'll give you another reason :-) > > If I do have multiple active struct consoles registered (e.g. normal tty0 or > ttyS0 and a debug console without a real tty), and the /dev/console demux > thinks the debug console is the real one (the one opened if you open > /dev/console), printk() messages will appear on both active consoles, but > /dev/console cannot be opened. > > To avoid this problem, the /dev/console demux should walk the list of active > consoles until it finds one that can be opened, or fall back to /dev/null if > none is found. > > Does that sound reasonable?
Not to me, no. But I was wrong before.
Having no console at all is a valid design. It used to cause problems, my patch fixes them. A command-line option like "console=/dev/null" doesn't fix it because it doesn't do what it appears to do at first glance, so the patch is needed.
Having a non-working console, esp. for debug, is a rather odd design. My approach would be to either explicitly tell the kernel to use the other as default console via "console=/dev/ttyS0" or not have the debug thing in the kernel in the first place. Either way, no patch is needed.
Worse, a kernel patch would paper over what is an underlying problem in my book. Fix the first problem, don't live with it as good as possible.
Is this reasonable?
Jörn
-- The competent programmer is fully aware of the strictly limited size of his own skull; therefore he approaches the programming task in full humility, and among other things he avoids clever tricks like the plague. -- Edsger W. Dijkstra - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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