drivers/gpu/drm/drm_vblank.c:883:20: warning: Local variable crtc shadows outer variable

drivers/gpu/drm/drm_vblank.c:883:20: warning: Local variable crtc shadows outer variable

[kernel test robot]

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CC: kbuild-all(a)lists.01.org
CC: linux-kernel(a)vger.kernel.org
TO: Thomas Zimmermann <tzimmermann@suse.de>
CC: "Ville Syrjälä" <ville.syrjala@linux.intel.com>

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   fc4f28bb3daf3265d6bc5f73b497306985bb23ab
commit: 7fe3f0d15aac6c98a97e6d7086f5a6b7bc4ccae4 drm: Add get_vblank_timestamp() to struct drm_crtc_funcs
date:   7 months ago
:::::: branch date: 9 hours ago
:::::: commit date: 7 months ago
compiler: h8300-linux-gcc (GCC) 9.3.0

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


cppcheck warnings: (new ones prefixed by >>)

>> drivers/gpu/drm/drm_vblank.c:883:20: warning: Local variable crtc shadows outer variable [shadowVar]
     struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
                      ^
   drivers/gpu/drm/drm_vblank.c:875:19: note: Shadowed declaration
    struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
                     ^
   drivers/gpu/drm/drm_vblank.c:883:20: note: Shadow variable
     struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
                      ^

# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7fe3f0d15aac6c98a97e6d7086f5a6b7bc4ccae4
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 7fe3f0d15aac6c98a97e6d7086f5a6b7bc4ccae4
vim +883 drivers/gpu/drm/drm_vblank.c

7fe3f0d15aac6c Thomas Zimmermann 2020-01-23  849  
3ed4351a83ca05 Daniel Vetter     2017-05-31  850  /**
3ed4351a83ca05 Daniel Vetter     2017-05-31  851   * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
3ed4351a83ca05 Daniel Vetter     2017-05-31  852   *                             vblank interval
3ed4351a83ca05 Daniel Vetter     2017-05-31  853   * @dev: DRM device
3ed4351a83ca05 Daniel Vetter     2017-05-31  854   * @pipe: index of CRTC whose vblank timestamp to retrieve
67680d3c046450 Arnd Bergmann     2017-10-11  855   * @tvblank: Pointer to target time which should receive the timestamp
3ed4351a83ca05 Daniel Vetter     2017-05-31  856   * @in_vblank_irq:
3ed4351a83ca05 Daniel Vetter     2017-05-31  857   *     True when called from drm_crtc_handle_vblank().  Some drivers
3ed4351a83ca05 Daniel Vetter     2017-05-31  858   *     need to apply some workarounds for gpu-specific vblank irq quirks
3ed4351a83ca05 Daniel Vetter     2017-05-31  859   *     if flag is set.
3ed4351a83ca05 Daniel Vetter     2017-05-31  860   *
3ed4351a83ca05 Daniel Vetter     2017-05-31  861   * Fetches the system timestamp corresponding to the time of the most recent
3ed4351a83ca05 Daniel Vetter     2017-05-31  862   * vblank interval on specified CRTC. May call into kms-driver to
3ed4351a83ca05 Daniel Vetter     2017-05-31  863   * compute the timestamp with a high-precision GPU specific method.
3ed4351a83ca05 Daniel Vetter     2017-05-31  864   *
3ed4351a83ca05 Daniel Vetter     2017-05-31  865   * Returns zero if timestamp originates from uncorrected do_gettimeofday()
3ed4351a83ca05 Daniel Vetter     2017-05-31  866   * call, i.e., it isn't very precisely locked to the true vblank.
3ed4351a83ca05 Daniel Vetter     2017-05-31  867   *
3ed4351a83ca05 Daniel Vetter     2017-05-31  868   * Returns:
3ed4351a83ca05 Daniel Vetter     2017-05-31  869   * True if timestamp is considered to be very precise, false otherwise.
3ed4351a83ca05 Daniel Vetter     2017-05-31  870   */
3ed4351a83ca05 Daniel Vetter     2017-05-31  871  static bool
3ed4351a83ca05 Daniel Vetter     2017-05-31  872  drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe,
67680d3c046450 Arnd Bergmann     2017-10-11  873  			  ktime_t *tvblank, bool in_vblank_irq)
3ed4351a83ca05 Daniel Vetter     2017-05-31  874  {
7fe3f0d15aac6c Thomas Zimmermann 2020-01-23  875  	struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
3ed4351a83ca05 Daniel Vetter     2017-05-31  876  	bool ret = false;
3ed4351a83ca05 Daniel Vetter     2017-05-31  877  
3ed4351a83ca05 Daniel Vetter     2017-05-31  878  	/* Define requested maximum error on timestamps (nanoseconds). */
3ed4351a83ca05 Daniel Vetter     2017-05-31  879  	int max_error = (int) drm_timestamp_precision * 1000;
3ed4351a83ca05 Daniel Vetter     2017-05-31  880  
3ed4351a83ca05 Daniel Vetter     2017-05-31  881  	/* Query driver if possible and precision timestamping enabled. */
7fe3f0d15aac6c Thomas Zimmermann 2020-01-23  882  	if (crtc && crtc->funcs->get_vblank_timestamp && max_error > 0) {
7fe3f0d15aac6c Thomas Zimmermann 2020-01-23 @883  		struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
7fe3f0d15aac6c Thomas Zimmermann 2020-01-23  884  
7fe3f0d15aac6c Thomas Zimmermann 2020-01-23  885  		ret = crtc->funcs->get_vblank_timestamp(crtc, &max_error,
7fe3f0d15aac6c Thomas Zimmermann 2020-01-23  886  							tvblank, in_vblank_irq);
7fe3f0d15aac6c Thomas Zimmermann 2020-01-23  887  	} else if (dev->driver->get_vblank_timestamp && max_error > 0) {
3ed4351a83ca05 Daniel Vetter     2017-05-31  888  		ret = dev->driver->get_vblank_timestamp(dev, pipe, &max_error,
3ed4351a83ca05 Daniel Vetter     2017-05-31  889  							tvblank, in_vblank_irq);
7fe3f0d15aac6c Thomas Zimmermann 2020-01-23  890  	}
3ed4351a83ca05 Daniel Vetter     2017-05-31  891  
3ed4351a83ca05 Daniel Vetter     2017-05-31  892  	/* GPU high precision timestamp query unsupported or failed.
3ed4351a83ca05 Daniel Vetter     2017-05-31  893  	 * Return current monotonic/gettimeofday timestamp as best estimate.
3ed4351a83ca05 Daniel Vetter     2017-05-31  894  	 */
3ed4351a83ca05 Daniel Vetter     2017-05-31  895  	if (!ret)
25e1a79874eb38 Arnd Bergmann     2017-10-11  896  		*tvblank = ktime_get();
3ed4351a83ca05 Daniel Vetter     2017-05-31  897  
3ed4351a83ca05 Daniel Vetter     2017-05-31  898  	return ret;
3ed4351a83ca05 Daniel Vetter     2017-05-31  899  }
3ed4351a83ca05 Daniel Vetter     2017-05-31  900  

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