Re: [bug 2.5.69] xirc2ps_cs, irq 3: nobody cared, shutdown hangs

From: David Woodhouse <dwmw2@infradead.org>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Jeff Garzik <jgarzik@pobox.com>,
	Zwane Mwaikambo <zwane@linuxpower.ca>,
	Daniel Ritz <daniel.ritz@gmx.ch>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@diego.com>
Subject: Re: [bug 2.5.69] xirc2ps_cs, irq 3: nobody cared, shutdown hangs
Date: Sun, 11 May 2003 23:55:04 +0100	[thread overview]
Message-ID: <1052693703.15307.18.camel@imladris.demon.co.uk> (raw)
In-Reply-To: <1052689233.30506.1.camel@dhcp22.swansea.linux.org.uk>

On Sun, 2003-05-11 at 22:40, Alan Cox wrote:
> On Sul, 2003-05-11 at 23:08, David Woodhouse wrote:
> > PCMCIA has varying pin length for the CD pins and hence gives you a few
> > milliseconds of warning before the card is _actually_ disconnected.
> 
> Which is less than the worst case IRQ response time (or indeed on some
> PCs the worst case CPU hold off time for the PCI bus)

On some hardware. 

> > After that period of time has elapsed and the card is actually gone, you
> > _really_ don't want to be bitbanging its ports.
> > 
> > > Its quite safe to do so.
> > 
> > Not on all platforms.
> 
> On all that matters it is safe, the others are unfixable anyway

Said 'others' will tend to give you better worst-case IRQ latency than a
PeeCee with broken PCI host bridge and IDE controllers :)

And even if that weren't the case, you appear to be asserting that
because a problem may still be triggerable in a worst-case scenario with
certain hardware configurations, we shouldn't attempt to fix it at all.
With that I disagree.

-- 
dwmw2