Subject: Re: Test Patch: 2.5.69 Interrupt Latency
From: Paul Fulghum <paulkf@microgate.com>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
       johannes@erdfelt.com,
       USB development list <linux-usb-devel@lists.sourceforge.net>
In-Reply-To: <1053107295.2606.21.camel@toshiba>
References: <Pine.LNX.4.44L0.0305161307390.1171-100000@ida.rowland.org>
	 <1053107295.2606.21.camel@toshiba>
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Date: 16 May 2003 13:31:40 -0500
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On Fri, 2003-05-16 at 12:48, Paul Fulghum wrote:
> So always allowing suspend, and selectively doing the
> wakeup will cause:
> 1. thrashing for case of one port OC,
> other port OK with attached device.
> 2. prevent port with OC from doing resume
> after clearing OC condition.
> 
> For the case of all ports hardwired OC, this
> will work because you suspend the whole controller
> and never get a valid resume.

Just to add another argument to disallowing suspend
instead of qualifying wakeup:

In 99% of cases, with no OC, this won't come into play.
In .9% of cases, with transient OC, this won't delay suspend long.
In .01% of cases, with all hardwired OC ports, suspend does not matter.

Plus it cures the above problems #1 and #2.

If problem #1 occurs, I don't see that thrashing is
any better than not suspending at all.


-- 
Paul Fulghum
paulkf@microgate.com

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