From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48640) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wzth0-0001eW-8W for qemu-devel@nongnu.org; Wed, 25 Jun 2014 16:21:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Wztgs-0007jU-KJ for qemu-devel@nongnu.org; Wed, 25 Jun 2014 16:21:18 -0400 Message-ID: <53AB2E74.1050802@ilande.co.uk> Date: Wed, 25 Jun 2014 21:17:56 +0100 From: Mark Cave-Ayland MIME-Version: 1.0 References: <1401885899-16524-1-git-send-email-agraf@suse.de> <1401885899-16524-76-git-send-email-agraf@suse.de> <53A44548.7020605@ilande.co.uk> <53A48B28.8070808@ilande.co.uk> <53A85668.10505@suse.de> <53A8AD26.2050305@ilande.co.uk> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PULL 075/118] macio: handle non-block ATAPI DMA transfers List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: BALATON Zoltan Cc: Kevin Wolf , "qemu-ppc@nongnu.org" , Alexander Graf , qemu-devel On 24/06/14 11:53, BALATON Zoltan wrote: >> All I can say is that debugging this stuff isn't easy, particularly >> with MorphOS which has some rather unusual behaviours. But what we >> really need from you now over the next few days is for you to compare >> the debug output between the working and non-working cases and figure >> out if we can fix this in time for the 2.1 release. You have >> everything you need (including my acceptance test of booting both >> MorphOS and Darwin ISOs), so time to take a deep breath and begin what >> should be a challenging yet ultimately rewarding debugging process :) > > I'm still working on finding a solution for the exception problems with > OpenBIOS that prevent MorphOS from working and I failed to understand > the whole working of macio, DBDMA and the whole block layer so far but I > can try to debug it. Can you tell how to reproduce the problem with > Darwin? The Darwin images don't seem to work with -M mac99 either before > or after the patch so no regressions there. It's fairly simple to reproduce here: qemu-system-ppc -M g3beige -cdrom darwinppc-602.iso -boot d qemu-system-ppc -M g3beige -cdrom darwinppc-801.iso -boot d qemu-system-ppc -M mac99 -cdrom darwinppc-801.iso -boot d For -M g3beige then darwinppc-602.iso tends to hang just after the "ADB present" line just before it finds the CDROM. Rather annoyingly it seems to be a lot trickier to reproduce today than it was with my original tests, currently 1 in 8 boots compared to 1 in 3 when I did the OpenBIOS tests. Delays introduced by enabling debugging in pmac_ide_transfer() seem to make it easier to trigger, as does compiling with -O0 -g (slower) and also dropping the kernel FS cache. Maybe it's an existing timing bug that happens to be exacerbated by the patch? :/ Notes: Darwin 6.02 doesn't support -M mac99 (always hangs) AFAICT. Darwin 8.01 works but with -M mac99 IDE detection can take up to 30s or so. ATB, Mark.