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Subject: Re: [PATCH] sh: Avoid using IRQ0 on SH3 and SH4
To:     John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>,
        Guenter Roeck <linux@roeck-us.net>,
        Geert Uytterhoeven <geert@linux-m68k.org>
CC:     Yoshinori Sato <ysato@users.sourceforge.jp>,
        Rich Felker <dalias@libc.org>, <linux-sh@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
References: <fbfea3ad-d327-4ad5-ac9c-648c7ca3fe1f@roeck-us.net>
 <CAMuHMdUfXdCf_CQuWXpP72MzKFYvXg3Ud1VN_3Bd0RHxfLhVeQ@mail.gmail.com>
 <7b2c0d812280afaefee0c70a9aea00a0fcf84e3a.camel@physik.fu-berlin.de>
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 <29ad9e3d1a83d03190626ba66b7d71c833776982.camel@physik.fu-berlin.de>
From:   Sergey Shtylyov <s.shtylyov@omp.ru>
Organization: Open Mobile Platform
Message-ID: <941c0ebf-d55a-22f1-72d4-1397f44d3c3a@omp.ru>
Date:   Sat, 8 Jul 2023 23:55:52 +0300
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On 7/6/23 8:41 PM, John Paul Adrian Glaubitz wrote:

>> I tried rts7751r2dplus_defconfig with no modifications and the following minimized
>> qemu command line.
>>
>> qemu-system-sh4 -M r2d -kernel arch/sh/boot/zImage -serial null -serial stdio -nographic -monitor null
>>
>> This hangs after "heartbeat: version 0.1.2 loaded", so it doesn't
>> even get to the point where it would try to load a root file system.
>> After reverting this patch, I get
>> ---[ end Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) ]---
>> as expected.
>>
>> I tried with qemu version 6.2, 7.1, 7.2, and 8.0.
> 
> I'm curios to hear what Geert and Sergey have to say. 

   Sorry for a late reaction, I was busy reviewing some PATA patches and a static analyzer
work here, at OMP...

> I hope we don't have to revert this :-(.

   I think we should be able to find the root cause soon.
   I prolly should learn Qemu some day... :-)

> Adrian

MBR, Sergey