From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NYkBu-0001Ho-Mf for qemu-devel@nongnu.org; Sat, 23 Jan 2010 12:54:34 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NYkBp-0001HT-7T for qemu-devel@nongnu.org; Sat, 23 Jan 2010 12:54:33 -0500 Received: from [199.232.76.173] (port=44606 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NYk8o-00014x-0q for qemu-devel@nongnu.org; Sat, 23 Jan 2010 12:51:22 -0500 Received: from fmmailgate03.web.de ([217.72.192.234]:54985) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NYk8n-0003yf-DL for qemu-devel@nongnu.org; Sat, 23 Jan 2010 12:51:21 -0500 Message-ID: <4B5B3710.80000@web.de> Date: Sat, 23 Jan 2010 18:51:12 +0100 From: Jan Kiszka MIME-Version: 1.0 References: <4B5AF934.9070606@web.de> In-Reply-To: <4B5AF934.9070606@web.de> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigE605CB3953FBD1B38E8BCA9B" Sender: jan.kiszka@web.de Subject: [Qemu-devel] Re: no sound in MusicPal with qemu 0.12.2 List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: malc Cc: qemu-devel@nongnu.org, ondrej drbohlav This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigE605CB3953FBD1B38E8BCA9B Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Jan Kiszka wrote: > malc wrote: >> On Sat, 23 Jan 2010, ondrej drbohlav wrote: >> >>> Hi there, >>> >>> I have compiled qemu 0.12.2 on an x64 ubuntu (8.10) and run MusicPal >>> in it with SDL. >>> MusicPal works OK but there is no sound. >> Confirmed. >> >>> I have done essentially the same with qemu 0.11.1. The sound is there= >>> (thanks jki for suggesting a previous version). >>> >>> Please find below the configs and logs & contact me if additional inf= o >>> is needed. >>> >>> Cheers, Ondrej >>> >>> 1) qemu-0.12.2 >> [..snip..] >> >> Someone would have to bisect it. >=20 > Already done: it's b3a219883ebe21f55a8ee5e7e5b38b9eb309e9c0. But that > patch looks sane. I guess it just revealed a hidden bug in Musicpal's > i2c use. Need to dig deeper. Found, trivial patch on the way. >=20 >> BTW, Jan, 2e87c5b937444c1155073f7b10d630e0e383e5d8 doesn't quite do >> what i said helps[1] and conseqently musicpal enters an infinite loop >> again... >> >> [1] http://lists.gnu.org/archive/html/qemu-devel/2009-09/msg00920.html= >> >=20 > OK, I will have to look into the Linux driver code to check the loop > termination conditions again. This still makes no sense, at least based on available driver sources and so far observed behavior with existing firmware images: the TX queue is always setup to form a ring, at no point the driver destroys this ring before triggering a TX. So we are only left with a potentially undefined (NULL) ring entry pointer, and that is what my commit tried to catch. I rather suspect we see a subtle memory corruption here. Malc, when do you get this? Could you instrument the loop to check if we get off-track before, scanning random guest memory? Jan --------------enigE605CB3953FBD1B38E8BCA9B Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iEYEARECAAYFAktbNxQACgkQitSsb3rl5xQBGwCgnjrt2yQnI6RuQ4KX22Ah3kah /8EAoNFS1ntbWKLeQBHWkvr0fIkwug9B =I1OC -----END PGP SIGNATURE----- --------------enigE605CB3953FBD1B38E8BCA9B--