Re: Linux 5.19-rc6

From: Guenter Roeck <linux@roeck-us.net>
To: Linus Torvalds <torvalds@linux-foundation.org>,
	Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Alex Deucher <alexdeucher@gmail.com>,
	Harry Wentland <harry.wentland@amd.com>,
	Leo Li <sunpeng.li@amd.com>,
	Alex Deucher <alexander.deucher@amd.com>,
	Balbir Singh <bsingharora@gmail.com>,
	Daniel Axtens <dja@axtens.net>,
	Paul Mackerras <paulus@ozlabs.org>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Kefeng Wang <wangkefeng.wang@huawei.com>,
	"Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	amd-gfx list <amd-gfx@lists.freedesktop.org>
Subject: Re: Linux 5.19-rc6
Date: Thu, 14 Jul 2022 10:24:22 -0700	[thread overview]
Message-ID: <6d5ac61b-b490-4f9d-6521-a4b7477d6fd2@roeck-us.net> (raw)
In-Reply-To: <CAHk-=wgnmaTVigBc02tjqgcZaNJiYz8Xw77P+ERAXhcYjkwd=Q@mail.gmail.com>

On 7/14/22 09:48, Linus Torvalds wrote:
> On Thu, Jul 14, 2022 at 12:23 AM Geert Uytterhoeven
> <geert@linux-m68k.org> wrote:
>>
>> Oh, it's not just this one. The lists of build regressions between v5.18
>> and v5.19-rc1 [1] resp. v5.19-rc6 [2] look surprisingly similar :-(
>>
>> [1] https://lore.kernel.org/all/20220606082201.2792145-1-geert@linux-m68k.org
>> [2] https://lore.kernel.org/all/20220711064425.3084093-1-geert@linux-m68k.org
> 
> Hmm.
> 
> Some of them are because UM ends up defining and exposing helper
> functions like "to_phys()", which it just shouldn't do. Very generic
> name - so when some driver ends up using the same name, you get those
> errors.

We can't use virt_to_phys() and phys_to_virt() because they are defined for
the underlying architecture. Would uml_to_phys() and uml_to_virt() be
acceptable ? If so, I'll submit a patch.

> 
> And some look positively strange. Like that
> 
>    drivers/mfd/asic3.c: error: unused variable 'asic'
> [-Werror=unused-variable]:  => 941:23
> 
> which is clearly used three lines later by
> 
>          iounmap(asic->tmio_cnf);
> 
> and I can't find any case of 'iounmap()' having been defined to an
> empty macro or anything like that to explain it. The error in
> drivers/tty/serial/sh-sci.c looks to be exactly the same issue, just
> with ioremap() instead of iounmap().
> 
> It would be good to have some way to find which build/architecture it
> is, because right now it just looks bogus.
> 
> Do you perhaps use some broken compiler that complains when the empty
> inline functions don't use their arguments? Because that's what those
> ioremap/iounmap() ones look like to me, but there might be some
> magical architecture / config that has issues that aren't obvious.
> 
> IOW, I'd love to get those fixed, but I would also want a little bit more info.
> 
Geert gave the necessary hint - it looks like sh-nommu used defines
for iomap() and iounmap(), which made the variable unused. According
to Geert that was fixed a couple of days ago.

Guenter