From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1KQOF6-0006lj-Sz
	for qemu-devel@nongnu.org; Tue, 05 Aug 2008 11:14:33 -0400
Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1KQOF4-0006lN-H4
	for qemu-devel@nongnu.org; Tue, 05 Aug 2008 11:14:31 -0400
Received: from [199.232.76.173] (port=41693 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1KQOF4-0006lJ-9b
	for qemu-devel@nongnu.org; Tue, 05 Aug 2008 11:14:30 -0400
Received: from smtp.eu.citrix.com ([62.200.22.115]:28373)
	by monty-python.gnu.org with esmtp (Exim 4.60)
	(envelope-from <Stefano.Stabellini@eu.citrix.com>)
	id 1KQOF4-0006TE-1P
	for qemu-devel@nongnu.org; Tue, 05 Aug 2008 11:14:30 -0400
Message-ID: <48986EA3.4070405@eu.citrix.com>
Date: Tue, 05 Aug 2008 16:15:47 +0100
From: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
MIME-Version: 1.0
Subject: Re: [Qemu-devel] [PATCH] upgrading emulated UART to 16550A
References: <48985284.9060001@eu.citrix.com> <48986B89.8000608@windriver.com>
In-Reply-To: <48986B89.8000608@windriver.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Reply-To: qemu-devel@nongnu.org
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/pipermail/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Jason Wessel <jason.wessel@windriver.com>
Cc: Ian Jackson <Ian.Jackson@eu.citrix.com>, qemu-devel@nongnu.org

Jason Wessel wrote:

> I didn't spend the time to figure out what was wrong, but I thought I'd
> try your new port emulation against KGDB which is known to work with
> real hardware, as well as the existing 16450 qemu uart support.
> 
> For some reason, the initial interrupt if a character comes into the
> uart does not seem to get raised, so the kernel routine which handles
> the traffic never gets invoked.  It is possible that the that the kgdb
> kernel driver has a defect, but this does seem to work on real hardware,
> so perhaps it is a timing problem or the qemu emulation is not quite
> accurate with respect to the real hardware.
> 
> If you like, I can provide you a bzImage and the qemu invocation, such
> that you could see the problem first hand.
> 

yeah, that could help.