Re: [PATCH] pinctrl: zynq: Use define directive for PIN_CONFIG_IO_STANDARD

[Nathan Chancellor <natechancellor@gmail.com>]

On Thu, Nov 08, 2018 at 07:45:42AM +0100, Michal Simek wrote:
> On 07. 11. 18 18:48, Nick Desaulniers wrote:
> > On Wed, Nov 7, 2018 at 1:01 AM Michal Simek <michal.simek@xilinx.com> wrote:
> >>
> >> On 07. 11. 18 9:55, Nathan Chancellor wrote:
> >>> On Wed, Nov 07, 2018 at 09:46:12AM +0100, Michal Simek wrote:
> >>>> On 01. 11. 18 1:57, Nathan Chancellor wrote:
> >>>>> Clang warns when one enumerated type is implicitly converted to another:
> >>>>>
> >>>>> drivers/pinctrl/pinctrl-zynq.c:985:18: warning: implicit conversion from
> >>>>> enumeration type 'enum zynq_pin_config_param' to different enumeration
> >>>>> type 'enum pin_config_param' [-Wenum-conversion]
> >>>>>         {"io-standard", PIN_CONFIG_IOSTANDARD, zynq_iostd_lvcmos18},
> >>>>>         ~               ^~~~~~~~~~~~~~~~~~~~~
> >>>>> drivers/pinctrl/pinctrl-zynq.c:990:16: warning: implicit conversion from
> >>>>> enumeration type 'enum zynq_pin_config_param' to different enumeration
> >>>>> type 'enum pin_config_param' [-Wenum-conversion]
> >>>>>         = { PCONFDUMP(PIN_CONFIG_IOSTANDARD, "IO-standard", NULL, true),
> >>>>>             ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >>>>> ./include/linux/pinctrl/pinconf-generic.h:163:11: note: expanded from
> >>>>> macro 'PCONFDUMP'
> >>>>>         .param = a, .display = b, .format = c, .has_arg = d     \
> >>>>>                  ^
> >>>>> 2 warnings generated.
> >>>>
> >>>> This is interesting. I have never tried to use llvm for building the
> >>>> kernel. Do you have any description how this can be done?
> >>>>
> >>>
> >>> Depending on what version of Clang you have access to, it is usually just as
> >>> simple as running 'make ARCH=arm CC=clang CROSS_COMPILE=arm-linux-gnueabi-'.
> >>>
> >>> Clang 7.0+ is recommended but 6.0 might work too.
> >>
> >> TBH I would expect to download container and run this there to make sure
> >> that I don't break anything else.
> > 
> > This is the first request we've had for a container in order to test a
> > patch.  If it comes up again from other folks, I think it makes sense
> > to create one.  Until then, its nice to have.  It's definitely
> > overkill for this patch.
> 
> I have played with it to see that error and here are some steps I did.
> 
> docker run --name test-clang -it --rm debian:latest bash
> apt-get update
> apt-get install gcc-arm-linux-gnueabi gcc-aarch64-linux-gnu clang git bc
> build-essential bison flex make llvm vim libssl-dev sparse
> 
> git clone
> git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git --depth 1
> cd linux
> 
> export ARCH=arm64
> export CROSS_COMPILE=aarch64-linux-gnu-
> 
> make defconfig

This should also have 'CC=clang' because compiler detection happens in
Kconfig now so compiler flags get properly set. Other than that, looks
good and I was able to build pinctrl-zynq.o without any issues with
those commands.

Cheers!
Nathan

> make CC=clang drivers/pinctrl/pinctrl-zynq.o C=1 V=1
> 
> There was not a problem to run it for arm64 but I had issues to run this
> for arm32.
> Do you see any problem with above steps?
> 
> Thanks,
> Michal
>