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Subject: Re: [PATCH v3] sh: avoid using IRQ0 on SH3/4
From:   Sergey Shtylyov <s.shtylyov@omp.ru>
To:     Rich Felker <dalias@libc.org>,
        John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
CC:     <linux-sh@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        Yoshinori Sato <ysato@users.sourceforge.jp>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 <11021433-66c0-3c56-42bd-207a5ae8d267@physik.fu-berlin.de>
 <20220429171623.GQ7074@brightrain.aerifal.cx>
 <525e7383-d26a-fe35-7005-e1dd9b57f76f@omp.ru>
Organization: Open Mobile Platform
Message-ID: <86b6c752-0599-d878-bff4-7d3d7b84176a@omp.ru>
Date:   Sun, 1 May 2022 21:09:24 +0300
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On 5/1/22 8:58 PM, Sergey Shtylyov wrote:
[...]
>>>> Using IRQ0 by the platform devices is going to be disallowed soon (see [1])
>>>> and even now, when IRQ0 is about to be returned by platfrom_get_irq(), you
>>>> see a big warning.  The code supporting SH3/4 SoCs maps the IRQ #s starting
>>>> at 0 -- modify that code to start the IRQ #s from 16 instead.
>>>>
>>>> The patch should mostly affect the AP-SH4A-3A/AP-SH4AD-0A boards as they
>>>> indeed use IRQ0 for the SMSC911x compatible Ethernet chip...
>>>
>>> Maybe try getting it landed through Andrew Morton's tree?
>>
>> Hi. I'm alive and looking at it. If it needs to go in for this cycle I
>> will send a pull request for just this and anything else critical. Was
> 
>    Well, now using IRQ0 just causes a WARNing in platform_get_irq() -- I don't
> think fixing it is critical enough. Starting from 5.19-rc1 the SMSC91xx driver
> should stop working on the mentioned boards.
>    But let me look at the SMSC driver itself, I haven't done this yet...

   Looks like these boards were borked back in 2015 by this commit:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=965b2aa78fbcb831acf4f669f494da201f4bcace

   It stopped accepting IRQ0 for no apparent reason. :-/

[...]

>> Rich

MBR, Sergey