From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:51029) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S8LPh-00014n-OM for qemu-devel@nongnu.org; Thu, 15 Mar 2012 20:53:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1S8LPf-00017H-MG for qemu-devel@nongnu.org; Thu, 15 Mar 2012 20:53:01 -0400 Received: from mail-we0-f173.google.com ([74.125.82.173]:34534) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S8LPf-00017C-DS for qemu-devel@nongnu.org; Thu, 15 Mar 2012 20:52:59 -0400 Received: by werp12 with SMTP id p12so3951537wer.4 for ; Thu, 15 Mar 2012 17:52:57 -0700 (PDT) From: Marek Vasut Date: Fri, 16 Mar 2012 01:52:55 +0100 References: <4E859A76.2000808@siemens.com> <201203151912.47455.marek.vasut@gmail.com> <4F6264EF.90709@web.de> In-Reply-To: <4F6264EF.90709@web.de> MIME-Version: 1.0 Content-Type: Text/Plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Message-Id: <201203160152.55783.marek.vasut@gmail.com> Subject: Re: [Qemu-devel] [PATCH 2/2] Drop obsolete nographic timer List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: Blue Swirl , Anthony Liguori , qemu-devel@nongnu.org Dear Jan Kiszka, > On 2012-03-15 19:12, Marek Vasut wrote: > > Dear Marek Vasut, > > > >> Dear Jan Kiszka, > >> > >>> On 2012-03-10 07:19, Marek Vasut wrote: > >>>> Dear Jan Kiszka, > >>>> > >>>>> We flush coalesced MMIO in the device models now, and VNC - for which > >>>>> this was once introduced - is also fine without it as it has its own > >>>>> refresh timer. > >>>>> > >>>>> Signed-off-by: Jan Kiszka > >>>>> --- > >>>>> > >>>>> vl.c | 13 ------------- > >>>>> 1 files changed, 0 insertions(+), 13 deletions(-) > >>>> > >>>> This patch seems to break QEMU/PXA emulation for me on the ZipitZ2 > >>>> platform. The serial console became very slow, but only when I type > >>>> something in. The output from the device to the console is ok. After > >>>> reverting this particular one, the console behaves normally. > >>> > >>> Removing that timer removal likely just revealed some formerly hidden > >>> bug. Can you share the command line used for starting and some test > >>> image? > >>> > >>> Jan > >> > >> qemu-system-arm -M z2 -pflash flash.img -serial null -serial null > >> -serial stdio -display none > >> > >> flash.img attached (XZ-ed) > > > > Bump? > > I had a brief look: The guest is apparently polling the uart, IRQ > delivery is disabled. Yes, it is. > But it also receives no timer ticks. I haven't > checked how it progresses, maybe there is some loop counter used. What do you mean? How does the timer implementation in pxa-uboot work? udelay() calls on the guest (pxa-uboot) simply poll the timer until it reaches certain value. There's no paralelism going on at all. > > What's the origin of this test image? Have you checked it works properly > on real silicon? Yep. > I do not know how this platform looks like in reality, > how it should behave and should be programmed (by the guest), so I > really can't compare and analyze, sorry. I'm the maintainer, nice to meet you ;-) Real silicon is a small clamshell pc- like device. But this breaks all xscale stuff in qemu. > > Jan Best regards, Marek Vasut