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Date: Thu, 11 Jun 2009 19:40:45 +0300
From: Gleb Natapov <gleb@redhat.com>
Subject: Re: [Qemu-devel] Register uhci_reset() callback.
Message-ID: <20090611164045.GA954@redhat.com>
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To: Jamie Lokier <jamie@shareable.org>
Cc: Paul Brook <paul@codesourcery.com>, qemu-devel@nongnu.org

On Thu, Jun 11, 2009 at 05:38:03PM +0100, Jamie Lokier wrote:
> Gleb Natapov wrote:
> > RHEL4.8 hangs after reboot because usb interrupt is not goes away. This
> > patch fixes it. Reseting all devices on a system reset is a right thing to do
> > even if there is no reproducible bug exist. 
> 
> I've got real hardware with this problem!  It doesn't reset the USB
> hardware (with some kinds of reset), and after reset the kernel runs
> about 100x too slow because it's getting a high rate of USB
> interrupts, until it loads the USB driver.
> 
> In the real hardware the solution is to explicitly shut down the USB
> chip prior to manual reset, and fortunately the watchdog/power-on
> resets do reset the USB chip anyway.
> 
> So I definitely support the idea that all components should be reset
> on a system reset event :-)
> 
> Now, a CPU-only reset, such as triple fault on x86, that's a bit different.
> 
On x86 triple fault wired to system reset.

--
			Gleb.