Re: [PATCH v2 3/5] vgaarb: mark vga_get family as __must_check

[kernel test robot <lkp@intel.com>]

Hi Simon,

kernel test robot noticed the following build errors:

[auto build test ERROR on pci/next]
[also build test ERROR on pci/for-linus drm-misc/drm-misc-next drm/drm-next linus/master v6.19 next-20260220]
[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#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Simon-Richter/vgaarb-pass-vga_get-errors-to-userspace/20260218-214939
base:   https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git next
patch link:    https://lore.kernel.org/r/20260218134633.461181-4-Simon.Richter%40hogyros.de
patch subject: [PATCH v2 3/5] vgaarb: mark vga_get family as __must_check
config: x86_64-randconfig-072-20250919 (https://download.01.org/0day-ci/archive/20260223/202602230802.stvvFCIZ-lkp@intel.com/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260223/202602230802.stvvFCIZ-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202602230802.stvvFCIZ-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/gpu/drm/i915/display/intel_vga.c: In function 'intel_vga_disable':
>> drivers/gpu/drm/i915/display/intel_vga.c:68:9: error: ignoring return value of 'vga_get_uninterruptible' declared with attribute 'warn_unused_result' [-Werror=unused-result]
      68 |         vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO);
         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/gpu/drm/i915/display/intel_vga.c: In function 'intel_vga_reset_io_mem':
   drivers/gpu/drm/i915/display/intel_vga.c:93:9: error: ignoring return value of 'vga_get_uninterruptible' declared with attribute 'warn_unused_result' [-Werror=unused-result]
      93 |         vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO);
         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   cc1: all warnings being treated as errors


vim +68 drivers/gpu/drm/i915/display/intel_vga.c

0c80d60ae63461 Ville Syrjälä 2025-04-17  43  
4fb8783165b7c6 Jani Nikula   2019-10-01  44  /* Disable the VGA plane that we never use */
4b6e05c43b7542 Ville Syrjälä 2024-09-06  45  void intel_vga_disable(struct intel_display *display)
4fb8783165b7c6 Jani Nikula   2019-10-01  46  {
4b6e05c43b7542 Ville Syrjälä 2024-09-06  47  	struct pci_dev *pdev = to_pci_dev(display->drm->dev);
4b6e05c43b7542 Ville Syrjälä 2024-09-06  48  	i915_reg_t vga_reg = intel_vga_cntrl_reg(display);
0c80d60ae63461 Ville Syrjälä 2025-04-17  49  	enum pipe pipe;
0c80d60ae63461 Ville Syrjälä 2025-04-17  50  	u32 tmp;
4fb8783165b7c6 Jani Nikula   2019-10-01  51  	u8 sr1;
4fb8783165b7c6 Jani Nikula   2019-10-01  52  
0c80d60ae63461 Ville Syrjälä 2025-04-17  53  	tmp = intel_de_read(display, vga_reg);
0c80d60ae63461 Ville Syrjälä 2025-04-17  54  	if (tmp & VGA_DISP_DISABLE)
a3af0140663dc3 Emil Velikov  2021-06-04  55  		return;
a3af0140663dc3 Emil Velikov  2021-06-04  56  
0c80d60ae63461 Ville Syrjälä 2025-04-17  57  	if (display->platform.cherryview)
0c80d60ae63461 Ville Syrjälä 2025-04-17  58  		pipe = REG_FIELD_GET(VGA_PIPE_SEL_MASK_CHV, tmp);
0c80d60ae63461 Ville Syrjälä 2025-04-17  59  	else if (has_vga_pipe_sel(display))
0c80d60ae63461 Ville Syrjälä 2025-04-17  60  		pipe = REG_FIELD_GET(VGA_PIPE_SEL_MASK, tmp);
0c80d60ae63461 Ville Syrjälä 2025-04-17  61  	else
0c80d60ae63461 Ville Syrjälä 2025-04-17  62  		pipe = PIPE_A;
0c80d60ae63461 Ville Syrjälä 2025-04-17  63  
0c80d60ae63461 Ville Syrjälä 2025-04-17  64  	drm_dbg_kms(display->drm, "Disabling VGA plane on pipe %c\n",
0c80d60ae63461 Ville Syrjälä 2025-04-17  65  		    pipe_name(pipe));
0c80d60ae63461 Ville Syrjälä 2025-04-17  66  
4fb8783165b7c6 Jani Nikula   2019-10-01  67  	/* WaEnableVGAAccessThroughIOPort:ctg,elk,ilk,snb,ivb,vlv,hsw */
4fb8783165b7c6 Jani Nikula   2019-10-01 @68  	vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO);
f0bb41fad02e03 Jani Nikula   2022-02-02  69  	outb(0x01, VGA_SEQ_I);
f0bb41fad02e03 Jani Nikula   2022-02-02  70  	sr1 = inb(VGA_SEQ_D);
f0bb41fad02e03 Jani Nikula   2022-02-02  71  	outb(sr1 | VGA_SR01_SCREEN_OFF, VGA_SEQ_D);
4fb8783165b7c6 Jani Nikula   2019-10-01  72  	vga_put(pdev, VGA_RSRC_LEGACY_IO);
4fb8783165b7c6 Jani Nikula   2019-10-01  73  	udelay(300);
4fb8783165b7c6 Jani Nikula   2019-10-01  74  
4b6e05c43b7542 Ville Syrjälä 2024-09-06  75  	intel_de_write(display, vga_reg, VGA_DISP_DISABLE);
4b6e05c43b7542 Ville Syrjälä 2024-09-06  76  	intel_de_posting_read(display, vga_reg);
4fb8783165b7c6 Jani Nikula   2019-10-01  77  }
4fb8783165b7c6 Jani Nikula   2019-10-01  78  

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