[drm-i915:for-linux-next 11/18] drivers/gpu/drm/i915/i915_switcheroo.c:21 i915_switcheroo_set_state() warn: variable dereferenced before check 'i915' (see line 18)

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

BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev
TO: Jani Nikula <jani.nikula@intel.com>
CC: Gustavo Sousa <gustavo.sousa@intel.com>

tree:   https://gitlab.freedesktop.org/drm/i915/kernel for-linux-next
head:   63e0b17ae79a4365e874d7e2ff3816db2e6d55b5
commit: d2e184f8e16ab85876ddcc0779358fbfe5162414 [11/18] drm/i915/switcheroo: pass display to HAS_DISPLAY()
:::::: branch date: 6 hours ago
:::::: commit date: 31 hours ago
config: i386-randconfig-141-20250815 (https://download.01.org/0day-ci/archive/20250816/202508160035.hmzuKiww-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)

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>
| Reported-by: Dan Carpenter <error27@gmail.com>
| Closes: https://lore.kernel.org/r/202508160035.hmzuKiww-lkp@intel.com/

smatch warnings:
drivers/gpu/drm/i915/i915_switcheroo.c:21 i915_switcheroo_set_state() warn: variable dereferenced before check 'i915' (see line 18)
drivers/gpu/drm/i915/i915_switcheroo.c:55 i915_switcheroo_can_switch() warn: variable dereferenced before check 'i915' (see line 48)

vim +/i915 +21 drivers/gpu/drm/i915/i915_switcheroo.c

63bf8301aac492 Jani Nikula       2019-10-04  13  
63bf8301aac492 Jani Nikula       2019-10-04  14  static void i915_switcheroo_set_state(struct pci_dev *pdev,
63bf8301aac492 Jani Nikula       2019-10-04  15  				      enum vga_switcheroo_state state)
63bf8301aac492 Jani Nikula       2019-10-04  16  {
63bf8301aac492 Jani Nikula       2019-10-04  17  	struct drm_i915_private *i915 = pdev_to_i915(pdev);
d2e184f8e16ab8 Jani Nikula       2025-08-06 @18  	struct intel_display *display = i915->display;
63bf8301aac492 Jani Nikula       2019-10-04  19  	pm_message_t pmm = { .event = PM_EVENT_SUSPEND };
63bf8301aac492 Jani Nikula       2019-10-04  20  
63bf8301aac492 Jani Nikula       2019-10-04 @21  	if (!i915) {
63bf8301aac492 Jani Nikula       2019-10-04  22  		dev_err(&pdev->dev, "DRM not initialized, aborting switch.\n");
63bf8301aac492 Jani Nikula       2019-10-04  23  		return;
63bf8301aac492 Jani Nikula       2019-10-04  24  	}
d2e184f8e16ab8 Jani Nikula       2025-08-06  25  	if (!HAS_DISPLAY(display)) {
a273e95721e968 Thomas Zimmermann 2023-01-16  26  		dev_err(&pdev->dev, "Device state not initialized, aborting switch.\n");
a273e95721e968 Thomas Zimmermann 2023-01-16  27  		return;
a273e95721e968 Thomas Zimmermann 2023-01-16  28  	}
63bf8301aac492 Jani Nikula       2019-10-04  29  
63bf8301aac492 Jani Nikula       2019-10-04  30  	if (state == VGA_SWITCHEROO_ON) {
f54efb6ad03322 Jani Nikula       2020-04-02  31  		drm_info(&i915->drm, "switched on\n");
63bf8301aac492 Jani Nikula       2019-10-04  32  		i915->drm.switch_power_state = DRM_SWITCH_POWER_CHANGING;
63bf8301aac492 Jani Nikula       2019-10-04  33  		/* i915 resume handler doesn't set to D0 */
63bf8301aac492 Jani Nikula       2019-10-04  34  		pci_set_power_state(pdev, PCI_D0);
b8d65b8a5aea33 Jani Nikula       2021-11-11  35  		i915_driver_resume_switcheroo(i915);
63bf8301aac492 Jani Nikula       2019-10-04  36  		i915->drm.switch_power_state = DRM_SWITCH_POWER_ON;
63bf8301aac492 Jani Nikula       2019-10-04  37  	} else {
f54efb6ad03322 Jani Nikula       2020-04-02  38  		drm_info(&i915->drm, "switched off\n");
63bf8301aac492 Jani Nikula       2019-10-04  39  		i915->drm.switch_power_state = DRM_SWITCH_POWER_CHANGING;
b8d65b8a5aea33 Jani Nikula       2021-11-11  40  		i915_driver_suspend_switcheroo(i915, pmm);
63bf8301aac492 Jani Nikula       2019-10-04  41  		i915->drm.switch_power_state = DRM_SWITCH_POWER_OFF;
63bf8301aac492 Jani Nikula       2019-10-04  42  	}
63bf8301aac492 Jani Nikula       2019-10-04  43  }
63bf8301aac492 Jani Nikula       2019-10-04  44  
63bf8301aac492 Jani Nikula       2019-10-04  45  static bool i915_switcheroo_can_switch(struct pci_dev *pdev)
63bf8301aac492 Jani Nikula       2019-10-04  46  {
63bf8301aac492 Jani Nikula       2019-10-04  47  	struct drm_i915_private *i915 = pdev_to_i915(pdev);
d2e184f8e16ab8 Jani Nikula       2025-08-06 @48  	struct intel_display *display = i915->display;
63bf8301aac492 Jani Nikula       2019-10-04  49  
63bf8301aac492 Jani Nikula       2019-10-04  50  	/*
63bf8301aac492 Jani Nikula       2019-10-04  51  	 * FIXME: open_count is protected by drm_global_mutex but that would lead to
63bf8301aac492 Jani Nikula       2019-10-04  52  	 * locking inversion with the driver load path. And the access here is
63bf8301aac492 Jani Nikula       2019-10-04  53  	 * completely racy anyway. So don't bother with locking for now.
63bf8301aac492 Jani Nikula       2019-10-04  54  	 */
d2e184f8e16ab8 Jani Nikula       2025-08-06 @55  	return i915 && HAS_DISPLAY(display) && atomic_read(&i915->drm.open_count) == 0;
63bf8301aac492 Jani Nikula       2019-10-04  56  }
63bf8301aac492 Jani Nikula       2019-10-04  57  

:::::: The code at line 21 was first introduced by commit
:::::: 63bf8301aac492d4c5fdf7b0ec42b142c05080e3 drm/i915: split out i915_switcheroo.[ch] from i915_drv.c

:::::: TO: Jani Nikula <jani.nikula@intel.com>
:::::: CC: Jani Nikula <jani.nikula@intel.com>

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