[kbuild-all] drivers/gpu/drm/drm_mipi_dbi.c:262:52: warning: Either the condition '!fb' is redundant or there is possible null pointer dereference: fb.

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: f40ddce88593482919761f74910f42f4b84c004b commit: 7e06886bbfca73717e45a0f20cdb4053793c191b drm/mipi-dbi: Remove ->enabled date: 8 months ago compiler: riscv64-linux-gcc (GCC) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; cppcheck possible warnings: (new ones prefixed by >>, may not real problems) struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev); ^ drivers/gpu/drm/drm_mipi_dbi.c:271:14: note: Assuming that condition '!fb' is not redundant if (WARN_ON(!fb)) ^ drivers/gpu/drm/drm_mipi_dbi.c:262:52: note: Null pointer dereference struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev); ^ vim +262 drivers/gpu/drm/drm_mipi_dbi.c f41a8a69890d08 drivers/gpu/drm/drm_mipi_dbi.c Geert Uytterhoeven 2020-01-15 257 af74138160e194 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-01-15 258 static void mipi_dbi_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect) 02dd95fe316936 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2017-01-22 259 { 7c9f1312cfca15 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-07-22 260 struct drm_gem_object *gem = drm_gem_fb_get_obj(fb, 0); 7c9f1312cfca15 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-07-22 261 struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(gem); 84137b866e834a drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-07-22 @262 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev); af74138160e194 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-01-15 263 unsigned int height = rect->y2 - rect->y1; af74138160e194 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-01-15 264 unsigned int width = rect->x2 - rect->x1; 84137b866e834a drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-07-22 265 struct mipi_dbi *dbi = &dbidev->dbi; 36b5057216236a drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-07-22 266 bool swap = dbi->swap_bytes; 9d5645ad1b979c drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-02-25 267 int idx, ret = 0; 02dd95fe316936 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2017-01-22 268 bool full; 02dd95fe316936 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2017-01-22 269 void *tr; 02dd95fe316936 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2017-01-22 270 7e06886bbfca73 drivers/gpu/drm/drm_mipi_dbi.c Daniel Vetter 2020-06-12 271 if (WARN_ON(!fb)) af74138160e194 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-01-15 272 return; 02dd95fe316936 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2017-01-22 273 9d5645ad1b979c drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-02-25 274 if (!drm_dev_enter(fb->dev, &idx)) 9d5645ad1b979c drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-02-25 275 return; 9d5645ad1b979c drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-02-25 276 af74138160e194 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-01-15 277 full = width == fb->width && height == fb->height; 02dd95fe316936 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2017-01-22 278 b051b3459bbae9 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-01-15 279 DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect)); 02dd95fe316936 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2017-01-22 280 36b5057216236a drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-07-22 281 if (!dbi->dc || !full || swap || 02dd95fe316936 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2017-01-22 282 fb->format->format == DRM_FORMAT_XRGB8888) { 440961d20959e8 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-07-22 283 tr = dbidev->tx_buf; 440961d20959e8 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-07-22 284 ret = mipi_dbi_buf_copy(dbidev->tx_buf, fb, rect, swap); 02dd95fe316936 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2017-01-22 285 if (ret) af74138160e194 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-01-15 286 goto err_msg; 02dd95fe316936 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2017-01-22 287 } else { 02dd95fe316936 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2017-01-22 288 tr = cma_obj->vaddr; 02dd95fe316936 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2017-01-22 289 } 02dd95fe316936 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2017-01-22 290 f41a8a69890d08 drivers/gpu/drm/drm_mipi_dbi.c Geert Uytterhoeven 2020-01-15 291 mipi_dbi_set_window_address(dbidev, rect->x1, rect->x2 - 1, rect->y1, f41a8a69890d08 drivers/gpu/drm/drm_mipi_dbi.c Geert Uytterhoeven 2020-01-15 292 rect->y2 - 1); 02dd95fe316936 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2017-01-22 293 36b5057216236a drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-07-22 294 ret = mipi_dbi_command_buf(dbi, MIPI_DCS_WRITE_MEMORY_START, tr, af74138160e194 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-01-15 295 width * height * 2); af74138160e194 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-01-15 296 err_msg: af74138160e194 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-01-15 297 if (ret) af74138160e194 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-01-15 298 dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret); 9d5645ad1b979c drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-02-25 299 9d5645ad1b979c drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2019-02-25 300 drm_dev_exit(idx); 02dd95fe316936 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2017-01-22 301 } 02dd95fe316936 drivers/gpu/drm/tinydrm/mipi-dbi.c Noralf Trønnes 2017-01-22 302 :::::: The code at line 262 was first introduced by commit :::::: 84137b866e834ac937582b04ae9bed0a72356a6a drm/tinydrm: Split struct mipi_dbi in two :::::: TO: Noralf Trønnes <noralf(a)tronnes.org&gt; :::::: CC: Noralf Trønnes <noralf(a)tronnes.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org