Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759498Ab3HOSFq (ORCPT ); Thu, 15 Aug 2013 14:05:46 -0400 Received: from mail-la0-f48.google.com ([209.85.215.48]:65259 "EHLO mail-la0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753334Ab3HOSFp (ORCPT ); Thu, 15 Aug 2013 14:05:45 -0400 MIME-Version: 1.0 In-Reply-To: <20130815175428.GA18580@roeck-us.net> References: <5207B3C3.9080508@roeck-us.net> <20130811220450.GY23006@n2100.arm.linux.org.uk> <52082EF8.10005@roeck-us.net> <20130813034054.GA18218@roeck-us.net> <20130815175428.GA18580@roeck-us.net> From: Peter Maydell Date: Thu, 15 Aug 2013 19:05:22 +0100 Message-ID: Subject: Re: [Qemu-devel] SCSI bus failures with qemu-arm in kernel 3.8+ To: Guenter Roeck Cc: Russell King - ARM Linux , Paul Gortmaker , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , QEMU Developers , Arnd Bergmann Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2890 Lines: 64 On 15 August 2013 18:54, Guenter Roeck wrote: > On Thu, Aug 15, 2013 at 05:45:42PM +0100, Peter Maydell wrote: >> On 13 August 2013 04:40, Guenter Roeck wrote: >> > Patch tested and working with qemu 1.5.2, using the configuration file >> > from the yocto project. Patch applied on top of kernel version 3.11-rc5. >> >> OK, I tested this on PB926+PCI backplane hardware, and it is >> definitely better than current mainline, in that the test USB >> card that I have no longer causes the kernel to generate this sort of >> backtrace: >> > Do you mean my patch fixes the traceback below as a side effect ? > Would be great ... it would be one more reason to get it applied. Yes, exactly -- the kernel currently has the wrong irq mapping, which causes the traceback (ie h/w asserts irq 93 but the kernel is listening on something else). That the patch fixes this confirms that it is the behaviour of hardware as well as of QEMU. >> However it still doesn't seem to reliably detect the USB harddisk >> plugged into the card, so I think there may be further issues, possibly >> some subset of those Arnd identified and fixed with this patch: >> http://permalink.gmane.org/gmane.linux.ports.arm.kernel/93397 >> > Does it get better if you apply Arnd's patch ? Arnd's patch is ancient and won't apply as is (due to intervening changes and also because some of the things it fixes were fixed in later patches); I'm currently trying to extract the relevant parts. If you want you can confirm that I/O port PCI access is broken on QEMU too -- disable CONFIG_SCSI_SYM53C8XX_MMIO so the driver uses PCI IO rather than MMIO and you'll see QEMU's SCSI device doesn't work any more. >> so I'd like to continue testing. >> >> The other thing this patch should (IMHO) have is the >> line in pci_versatile_setup() which tells QEMU that the >> kernel really does expect hardware-like behaviour: >> (Without this line QEMU will guess whether the kernel is broken >> or not and will get it right most but not necessarily all of the time.) >> > Might make sense, but I think it should be a separate patch. It needs to go in the same patch, because a kernel with the fixed irq remapping must also tell QEMU it is fixed; if you split the two then at the point between the two patches the kernel is broken for bisection purposes. > If I understand correctly, my patch fixes the SCSI problem. > Is that correct ? If so, can we get it applied to mainline ? I'd rather get to a point where I have the hardware definitely completely working first. There's no real hurry, this has been broken for months and months. -- PMM -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/