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

[Rong Chen]

On 8/7/20 7:53 PM, Luc Van Oostenryck wrote:
> 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?

Hi Luc,

Sorry for the inconvenience, we'll ignore this commit firstly.

> 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.
Thanks for your advice, we'll seriously consider it.

Best Regards,
Rong Chen