On 7/1/2021 10:40 AM, Nick Desaulniers wrote:
> On Thu, Jul 1, 2021 at 3:20 AM Arnd Bergmann <arnd@arndb.de> wrote:
>>
>> On Thu, Jul 1, 2021 at 12:38 AM kernel test robot <lkp@intel.com> wrote:
>>>
>>> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-4.4.y
>>> head:   38c92ba3580f0d00e57a55caf8f880aa1a0f2a50
>>> commit: 10a0c6746644a4fcaf1ffe2916387e17ba059517 [1401/1774] ARM: s3c: fix fiq for clang IAS
>>> config: arm-randconfig-r034-20210630 (attached as .config)
>>> compiler: arm-linux-gnueabi-gcc (GCC) 7.5.0
>>> reproduce (this is a W=1 build):
>>>          wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>>>          chmod +x ~/bin/make.cross
>>>          # https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git/commit/?id=10a0c6746644a4fcaf1ffe2916387e17ba059517
>>>          git remote add linux-stable-rc https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
>>>          git fetch --no-tags linux-stable-rc linux-4.4.y
>>>          git checkout 10a0c6746644a4fcaf1ffe2916387e17ba059517
>>>          # save the attached .config to linux build tree
>>>          mkdir build_dir
>>>          COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-7.5.0 make.cross O=build_dir ARCH=arm SHELL=/bin/bash drivers/
>>>
>>> If you fix the issue, kindly add following tag as appropriate
>>> Reported-by: kernel test robot <lkp@intel.com>
>>>
>>> All errors (new ones prefixed by >>):
>>>
>>>     drivers/spi/spi-s3c24xx-fiq.S: Assembler messages:
>>>>> drivers/spi/spi-s3c24xx-fiq.S:52: Error: bad instruction `subsne pc,lr,#4'
>>>     drivers/spi/spi-s3c24xx-fiq.S:78: Error: bad instruction `subsne pc,lr,#4'
>>>     drivers/spi/spi-s3c24xx-fiq.S:102: Error: bad instruction `subsne pc,lr,#4'
>>
>> Ah, this must be a kernel that never got the unified assembler syntax fixes
>> that this requires. It seems they went into linux-5.1 but nothing before that,
>> though they may have been backported.
>>
>> Nick or Nathan, what is the earliest lts kernel series that you would expect
>> to work with clang IAS?
> 
> 5.4+ for A32.
> 
>> Should we just drop these fixes for all 4.x.y versions?
> 
> Sure, but I'm curious what is missing here that exists further
> upstream?  subsne is the correct syntax, isn't it?

Isn't this unified syntax though? Unified syntax was not used 
universally until commit 75fea300d73a ("ARM: 8723/2: always assume the 
"unified" syntax for assembly code"). I backported that to 4.9 to fix 
this error, it seems like 4.4 needs it as well. I can test that and send 
it along.

Cheers,
Nathan