From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1KXhAM-0004Ki-P3 for qemu-devel@nongnu.org; Mon, 25 Aug 2008 14:51:50 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1KXhAL-0004KQ-4Q for qemu-devel@nongnu.org; Mon, 25 Aug 2008 14:51:50 -0400 Received: from [199.232.76.173] (port=53019 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1KXhAK-0004KN-Ts for qemu-devel@nongnu.org; Mon, 25 Aug 2008 14:51:48 -0400 Received: from moutng.kundenserver.de ([212.227.126.183]:56767) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1KXhAK-0001o5-FU for qemu-devel@nongnu.org; Mon, 25 Aug 2008 14:51:49 -0400 Message-ID: <48B2FF3A.3010208@mail.berlios.de> Date: Mon, 25 Aug 2008 20:51:38 +0200 From: Stefan Weil MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH] MIPS: Fix dmtc0 instruction References: <48B03DFA.6080404@reactos.org> <20080823172404.GK32516@volta.aurel32.net> <20080825112841.GB994@networkno.de> In-Reply-To: <20080825112841.GB994@networkno.de> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, Thiemo Seufer Thiemo Seufer schrieb: > I can confirm it works here as well, thank you. However, I still see > > QEMU hang with the debian kernel at IDE detection: > > [...] > [ 2.040127] pcnet32.c:v1.34-NAPI 14.Aug.2007 tsbogend@alpha.franken.de > [ 2.040127] pcnet32: PCnet/PCI II 79C970A at 0x1020, 52:54:00:12:34:56 > assigned IRQ 10. > [ 2.040127] eth0: registered as PCnet/PCI II 79C970A > [ 2.040127] pcnet32: 1 cards_found. > [ 2.040127] Uniform Multi-Platform E-IDE driver > [ 2.040127] ide: Assuming 33MHz system bus speed for PIO modes; > override with idebus=xx > [ 2.040127] PIIX4: IDE controller (0x8086:0x7111 rev 0x00) at PCI slot > 0000:00:0a.1 > [ 2.040127] PCI: Enabling device 0000:00:0a.1 (0000 -> 0001) > [ 2.040127] PIIX4: not 100% native mode: will probe irqs later > [ 2.040127] ide0: BM-DMA at 0x1040-0x1047, BIOS settings: hda:PIO, hdb:PIO > [ 2.040127] ide1: BM-DMA at 0x1048-0x104f, BIOS settings: hdc:PIO, hdd:PIO > > I figure CONFIG_NO_HZ has too high demands on the count/compare emulation. > > > Thiemo There is a problem with the current count/compare emulation: c0_compare_int_usable in newer Linux kernels fails to detect that it is usable. I had a Mips Linux kernel hanging while calibrating bogo mips caused by this. A workaround was running Qemu with all debug output enabled (-d ...), so a slower running Qemu was better. A crude workaround is here: http://svn.berlios.de/svnroot/repos/ar7-firmware/qemu/trunk/hw/mips_timer.c I don't really like my patch, but it improves count/compare emulation, and my kernel no longer hangs when running in Qemu. Maybe you can try it with your kernel. Stefan