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Date:   Tue, 14 Mar 2023 18:19:34 +0100
From:   "Arnd Bergmann" <arnd@arndb.de>
To:     "Florian Fainelli" <f.fainelli@gmail.com>,
        "Thomas Bogendoerfer" <tsbogend@alpha.franken.de>,
        "Baoquan He" <bhe@redhat.com>
Cc:     linux-kernel@vger.kernel.org,
        Linux-Arch <linux-arch@vger.kernel.org>, linux-mm@kvack.org,
        "Michael Ellerman" <mpe@ellerman.id.au>,
        "Geert Uytterhoeven" <geert@linux-m68k.org>,
        "Luis Chamberlain" <mcgrof@kernel.org>,
        "Christoph Hellwig" <hch@infradead.org>,
        "Helge Deller" <deller@gmx.de>,
        "Serge Semin" <fancer.lancer@gmail.com>,
        "Huacai Chen" <chenhuacai@kernel.org>,
        "Jiaxun Yang" <jiaxun.yang@flygoat.com>, linux-mips@vger.kernel.org
Subject: Re: [PATCH v4 2/4] mips: add <asm-generic/io.h> including
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On Tue, Mar 14, 2023, at 17:31, Florian Fainelli wrote:
> On 3/14/23 08:34, Thomas Bogendoerfer wrote:
>> On Tue, Mar 14, 2023 at 10:56:36AM +0800, Baoquan He wrote:
>>>> In file included from /local/tbogendoerfer/korg/linux/include/linux/spinlock.h:311:0,
>>>>                   from /local/tbogendoerfer/korg/linux/include/linux/vmalloc.h:5,
>>>>                   from /local/tbogendoerfer/korg/linux/include/asm-generic/io.h:994,
>>>>                   from /local/tbogendoerfer/korg/linux/arch/mips/include/asm/io.h:618,
>>>>                   from /local/tbogendoerfer/korg/linux/include/linux/io.h:13,
>>>>                   from /local/tbogendoerfer/korg/linux/arch/mips/include/asm/mips-cps.h:11,
>>>>                   from /local/tbogendoerfer/korg/linux/arch/mips/include/asm/smp-ops.h:16,
>>>>                   from /local/tbogendoerfer/korg/linux/arch/mips/include/asm/smp.h:21,
>>>>                   from /local/tbogendoerfer/korg/linux/include/linux/smp.h:113,
>>>>                   from /local/tbogendoerfer/korg/linux/include/linux/lockdep.h:14,
>>>>                   from /local/tbogendoerfer/korg/linux/include/linux/rcupdate.h:29,
>>>>                   from /local/tbogendoerfer/korg/linux/include/linux/rculist.h:11,
>>>>                   from /local/tbogendoerfer/korg/linux/include/linux/pid.h:5,
>>>>                   from /local/tbogendoerfer/korg/linux/include/linux/sched.h:14,
>>>>                   from /local/tbogendoerfer/korg/linux/include/linux/utsname.h:6,
>>>>                   from /local/tbogendoerfer/korg/linux/init/version.c:17:
>> 
>> already tried it, but it doesn't fix the issue. I've attached the
>> config.
>
> I had attempted a similar approach before as Baoquan did, but met the 
> same build issue as Thomas that was not immediately clear to me why it 
> popped up. I would be curious to see how this can be resolved.

I think this is the result of recursive header inclusion:
spinlock.h includes lockdep.h, but its header guard is already
there from the include chain.

There is probably something in one of the mips asm/*.h headers that
causes this recursion that is not present elsewhere.

I think this should fix it, but is likely to cause another problem elsewhere:

--- a/arch/mips/include/asm/smp-ops.h
+++ b/arch/mips/include/asm/smp-ops.h
@@ -13,8 +13,6 @@
 
 #include <linux/errno.h>
 
-#include <asm/mips-cps.h>
-
 #ifdef CONFIG_SMP
 
 #include <linux/cpumask.h>


    Arnd