Re: drivers/video/fbdev/pxafb.c:916:24: sparse: sparse: incorrect type in assignment (different address spaces)

[Luc Van Oostenryck]

On Fri, Aug 07, 2020 at 06:37:36PM +0800, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   86cfccb66937dd6cbf26ed619958b9e587e6a115
> commit: 670d0a4b10704667765f7d18f7592993d02783aa sparse: use identifiers to define address spaces
> date:   7 weeks ago
> config: arm-randconfig-s031-20200807 (attached as .config)
> compiler: arm-linux-gnueabi-gcc (GCC) 9.3.0
> reproduce:
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # apt-get install sparse
>         # sparse version: v0.6.2-118-ge1578773-dirty
>         git checkout 670d0a4b10704667765f7d18f7592993d02783aa
>         # save the attached .config to linux build tree
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=arm 
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> 
> 
> sparse warnings: (new ones prefixed by >>)
> 
> >> drivers/video/fbdev/pxafb.c:916:24: sparse: sparse: incorrect type in assignment (different address spaces) @@     expected void [noderef] __iomem *video_mem @@     got void * @@
> >> drivers/video/fbdev/pxafb.c:916:24: sparse:     expected void [noderef] __iomem *video_mem

Hi,

since late June I receive several mails per day about this commit but
they are all false-positive.
Commit 670d0a4b10704667765f7d18f7592993d02783aa can't introduce *new*
warnings, it only change how address-spaces are displayed in sparse's
warnings (for example, the address space for __user pointers were
displayd as '<asn:1>', now it's nicely displayed as '__user', same
for '__iomem', '__percpu' and '__rcu').

Isn't it possible to ignore some commits like this one?
Or, even better, should it be possible to only report when a new
warning is effectively added, not when its content is simply modified?
If not it would be nice to be able to see the difference in a diff-like
format.

Best regards,
-- Luc