Hi Bogdan,

I love your patch! Perhaps something to improve:

[auto build test WARNING on drm-intel/for-linux-next]
[also build test WARNING on drm-exynos/exynos-drm-next tegra-drm/drm/tegra/for-next linus/master v5.10-rc1 next-20201026]
[cannot apply to drm/drm-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Bogdan-Togorean/drm-adi-axi-hdmi-tx-Add-support-for-AXI-HDMI-TX-IP-core/20201026-144628
base:   git://anongit.freedesktop.org/drm-intel for-linux-next
config: powerpc-randconfig-r002-20201026 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project f2c25c70791de95d2466e09b5b58fc37f6ccd7a4)
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
        # install powerpc cross compiling tool for clang build
        # apt-get install binutils-powerpc-linux-gnu
        # https://github.com/0day-ci/linux/commit/3b750d1d27d13d89fd7b53ec7154dd2ae2cd36a5
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Bogdan-Togorean/drm-adi-axi-hdmi-tx-Add-support-for-AXI-HDMI-TX-IP-core/20201026-144628
        git checkout 3b750d1d27d13d89fd7b53ec7154dd2ae2cd36a5
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   In file included from drivers/gpu/drm/adi/axi_hdmi_tx_encoder.c:11:
   In file included from include/linux/io.h:13:
   In file included from arch/powerpc/include/asm/io.h:604:
   arch/powerpc/include/asm/io-defs.h:43:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   DEF_PCI_AC_NORET(insb, (unsigned long p, void *b, unsigned long c),
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                   __do_##name al;                                 \
                   ^~~~~~~~~~~~~~
   <scratch space>:231:1: note: expanded from here
   __do_insb
   ^
   arch/powerpc/include/asm/io.h:541:56: note: expanded from macro '__do_insb'
   #define __do_insb(p, b, n)      readsb((PCI_IO_ADDR)_IO_BASE+(p), (b), (n))
                                          ~~~~~~~~~~~~~~~~~~~~~^
   In file included from drivers/gpu/drm/adi/axi_hdmi_tx_encoder.c:11:
   In file included from include/linux/io.h:13:
   In file included from arch/powerpc/include/asm/io.h:604:
   arch/powerpc/include/asm/io-defs.h:45:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   DEF_PCI_AC_NORET(insw, (unsigned long p, void *b, unsigned long c),
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                   __do_##name al;                                 \
                   ^~~~~~~~~~~~~~
   <scratch space>:233:1: note: expanded from here
   __do_insw
   ^
   arch/powerpc/include/asm/io.h:542:56: note: expanded from macro '__do_insw'
   #define __do_insw(p, b, n)      readsw((PCI_IO_ADDR)_IO_BASE+(p), (b), (n))
                                          ~~~~~~~~~~~~~~~~~~~~~^
   In file included from drivers/gpu/drm/adi/axi_hdmi_tx_encoder.c:11:
   In file included from include/linux/io.h:13:
   In file included from arch/powerpc/include/asm/io.h:604:
   arch/powerpc/include/asm/io-defs.h:47:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   DEF_PCI_AC_NORET(insl, (unsigned long p, void *b, unsigned long c),
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                   __do_##name al;                                 \
                   ^~~~~~~~~~~~~~
   <scratch space>:235:1: note: expanded from here
   __do_insl
   ^
   arch/powerpc/include/asm/io.h:543:56: note: expanded from macro '__do_insl'
   #define __do_insl(p, b, n)      readsl((PCI_IO_ADDR)_IO_BASE+(p), (b), (n))
                                          ~~~~~~~~~~~~~~~~~~~~~^
   In file included from drivers/gpu/drm/adi/axi_hdmi_tx_encoder.c:11:
   In file included from include/linux/io.h:13:
   In file included from arch/powerpc/include/asm/io.h:604:
   arch/powerpc/include/asm/io-defs.h:49:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   DEF_PCI_AC_NORET(outsb, (unsigned long p, const void *b, unsigned long c),
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                   __do_##name al;                                 \
                   ^~~~~~~~~~~~~~
   <scratch space>:237:1: note: expanded from here
   __do_outsb
   ^
   arch/powerpc/include/asm/io.h:544:58: note: expanded from macro '__do_outsb'
   #define __do_outsb(p, b, n)     writesb((PCI_IO_ADDR)_IO_BASE+(p),(b),(n))
                                           ~~~~~~~~~~~~~~~~~~~~~^
   In file included from drivers/gpu/drm/adi/axi_hdmi_tx_encoder.c:11:
   In file included from include/linux/io.h:13:
   In file included from arch/powerpc/include/asm/io.h:604:
   arch/powerpc/include/asm/io-defs.h:51:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   DEF_PCI_AC_NORET(outsw, (unsigned long p, const void *b, unsigned long c),
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                   __do_##name al;                                 \
                   ^~~~~~~~~~~~~~
   <scratch space>:2:1: note: expanded from here
   __do_outsw
   ^
   arch/powerpc/include/asm/io.h:545:58: note: expanded from macro '__do_outsw'
   #define __do_outsw(p, b, n)     writesw((PCI_IO_ADDR)_IO_BASE+(p),(b),(n))
                                           ~~~~~~~~~~~~~~~~~~~~~^
   In file included from drivers/gpu/drm/adi/axi_hdmi_tx_encoder.c:11:
   In file included from include/linux/io.h:13:
   In file included from arch/powerpc/include/asm/io.h:604:
   arch/powerpc/include/asm/io-defs.h:53:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   DEF_PCI_AC_NORET(outsl, (unsigned long p, const void *b, unsigned long c),
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                   __do_##name al;                                 \
                   ^~~~~~~~~~~~~~
   <scratch space>:4:1: note: expanded from here
   __do_outsl
   ^
   arch/powerpc/include/asm/io.h:546:58: note: expanded from macro '__do_outsl'
   #define __do_outsl(p, b, n)     writesl((PCI_IO_ADDR)_IO_BASE+(p),(b),(n))
                                           ~~~~~~~~~~~~~~~~~~~~~^
>> drivers/gpu/drm/adi/axi_hdmi_tx_encoder.c:77:23: warning: unused variable 'adv7511_csc_ycbcr_to_rgb' [-Wunused-const-variable]
   static const uint16_t adv7511_csc_ycbcr_to_rgb[] = {
                         ^
   7 warnings generated.
--
   In file included from drivers/gpu/drm/adi/axi_hdmi_tx_drv.c:13:
   In file included from include/linux/of_address.h:7:
   In file included from include/linux/io.h:13:
   In file included from arch/powerpc/include/asm/io.h:604:
   arch/powerpc/include/asm/io-defs.h:43:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   DEF_PCI_AC_NORET(insb, (unsigned long p, void *b, unsigned long c),
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                   __do_##name al;                                 \
                   ^~~~~~~~~~~~~~
   <scratch space>:199:1: note: expanded from here
   __do_insb
   ^
   arch/powerpc/include/asm/io.h:541:56: note: expanded from macro '__do_insb'
   #define __do_insb(p, b, n)      readsb((PCI_IO_ADDR)_IO_BASE+(p), (b), (n))
                                          ~~~~~~~~~~~~~~~~~~~~~^
   In file included from drivers/gpu/drm/adi/axi_hdmi_tx_drv.c:13:
   In file included from include/linux/of_address.h:7:
   In file included from include/linux/io.h:13:
   In file included from arch/powerpc/include/asm/io.h:604:
   arch/powerpc/include/asm/io-defs.h:45:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   DEF_PCI_AC_NORET(insw, (unsigned long p, void *b, unsigned long c),
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                   __do_##name al;                                 \
                   ^~~~~~~~~~~~~~
   <scratch space>:201:1: note: expanded from here
   __do_insw
   ^
   arch/powerpc/include/asm/io.h:542:56: note: expanded from macro '__do_insw'
   #define __do_insw(p, b, n)      readsw((PCI_IO_ADDR)_IO_BASE+(p), (b), (n))
                                          ~~~~~~~~~~~~~~~~~~~~~^
   In file included from drivers/gpu/drm/adi/axi_hdmi_tx_drv.c:13:
   In file included from include/linux/of_address.h:7:
   In file included from include/linux/io.h:13:
   In file included from arch/powerpc/include/asm/io.h:604:
   arch/powerpc/include/asm/io-defs.h:47:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   DEF_PCI_AC_NORET(insl, (unsigned long p, void *b, unsigned long c),
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                   __do_##name al;                                 \
                   ^~~~~~~~~~~~~~
   <scratch space>:203:1: note: expanded from here
   __do_insl
   ^
   arch/powerpc/include/asm/io.h:543:56: note: expanded from macro '__do_insl'
   #define __do_insl(p, b, n)      readsl((PCI_IO_ADDR)_IO_BASE+(p), (b), (n))
                                          ~~~~~~~~~~~~~~~~~~~~~^
   In file included from drivers/gpu/drm/adi/axi_hdmi_tx_drv.c:13:
   In file included from include/linux/of_address.h:7:
   In file included from include/linux/io.h:13:
   In file included from arch/powerpc/include/asm/io.h:604:
   arch/powerpc/include/asm/io-defs.h:49:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   DEF_PCI_AC_NORET(outsb, (unsigned long p, const void *b, unsigned long c),
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                   __do_##name al;                                 \
                   ^~~~~~~~~~~~~~
   <scratch space>:205:1: note: expanded from here
   __do_outsb
   ^
   arch/powerpc/include/asm/io.h:544:58: note: expanded from macro '__do_outsb'
   #define __do_outsb(p, b, n)     writesb((PCI_IO_ADDR)_IO_BASE+(p),(b),(n))
                                           ~~~~~~~~~~~~~~~~~~~~~^
   In file included from drivers/gpu/drm/adi/axi_hdmi_tx_drv.c:13:
   In file included from include/linux/of_address.h:7:
   In file included from include/linux/io.h:13:
   In file included from arch/powerpc/include/asm/io.h:604:
   arch/powerpc/include/asm/io-defs.h:51:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   DEF_PCI_AC_NORET(outsw, (unsigned long p, const void *b, unsigned long c),
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                   __do_##name al;                                 \
                   ^~~~~~~~~~~~~~
   <scratch space>:207:1: note: expanded from here
   __do_outsw
   ^
   arch/powerpc/include/asm/io.h:545:58: note: expanded from macro '__do_outsw'
   #define __do_outsw(p, b, n)     writesw((PCI_IO_ADDR)_IO_BASE+(p),(b),(n))
                                           ~~~~~~~~~~~~~~~~~~~~~^
   In file included from drivers/gpu/drm/adi/axi_hdmi_tx_drv.c:13:
   In file included from include/linux/of_address.h:7:
   In file included from include/linux/io.h:13:
   In file included from arch/powerpc/include/asm/io.h:604:
   arch/powerpc/include/asm/io-defs.h:53:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   DEF_PCI_AC_NORET(outsl, (unsigned long p, const void *b, unsigned long c),
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                   __do_##name al;                                 \
                   ^~~~~~~~~~~~~~
   <scratch space>:209:1: note: expanded from here
   __do_outsl
   ^
   arch/powerpc/include/asm/io.h:546:58: note: expanded from macro '__do_outsl'
   #define __do_outsl(p, b, n)     writesl((PCI_IO_ADDR)_IO_BASE+(p),(b),(n))
                                           ~~~~~~~~~~~~~~~~~~~~~^
>> drivers/gpu/drm/adi/axi_hdmi_tx_drv.c:137:6: warning: variable 'slave_node' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
           if (ep_node) {
               ^~~~~~~
   drivers/gpu/drm/adi/axi_hdmi_tx_drv.c:151:7: note: uninitialized use occurs here
           if (!slave_node)
                ^~~~~~~~~~
   drivers/gpu/drm/adi/axi_hdmi_tx_drv.c:137:2: note: remove the 'if' if its condition is always true
           if (ep_node) {
           ^~~~~~~~~~~~~
   drivers/gpu/drm/adi/axi_hdmi_tx_drv.c:116:32: note: initialize the variable 'slave_node' to silence this warning
           struct device_node *slave_node, *ep_node;
                                         ^
                                          = NULL
   7 warnings generated.

vim +/adv7511_csc_ycbcr_to_rgb +77 drivers/gpu/drm/adi/axi_hdmi_tx_encoder.c

    76	
  > 77	static const uint16_t adv7511_csc_ycbcr_to_rgb[] = {
    78		0x0734, 0x04ad, 0x0000, 0x1c1b,
    79		0x1ddc, 0x04ad, 0x1f24, 0x0135,
    80		0x0000, 0x04ad, 0x087c, 0x1b77,
    81	};
    82	

---
0-DAY CI Kernel Test Service, Intel Corporation
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