Hi Stanislav, url: https://github.com/0day-ci/linux/commits/Stanislav-Lisovskiy/drm-i915-Fix-wrong-CDCLK-adjustment-changes/20200526-180642 base: git://anongit.freedesktop.org/drm/drm-tip drm-tip config: i386-randconfig-m021-20200531 (attached as .config) compiler: gcc-9 (Debian 9.3.0-13) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot Reported-by: Dan Carpenter smatch warnings: drivers/gpu/drm/i915/display/intel_bw.c:453 skl_bw_calc_min_cdclk() error: uninitialized symbol 'pipe'. # https://github.com/0day-ci/linux/commit/21b0324886122a396687d977d67eb6ce3caf2b17 git remote add linux-review https://github.com/0day-ci/linux git remote update linux-review git checkout 21b0324886122a396687d977d67eb6ce3caf2b17 vim +/pipe +453 drivers/gpu/drm/i915/display/intel_bw.c 366b6200f76e0f Jani Nikula 2019-08-06 430 cd19154608610a Stanislav Lisovskiy 2020-05-20 431 int skl_bw_calc_min_cdclk(struct intel_atomic_state *state) cd19154608610a Stanislav Lisovskiy 2020-05-20 432 { cd19154608610a Stanislav Lisovskiy 2020-05-20 433 struct drm_i915_private *dev_priv = to_i915(state->base.dev); cac91e671ad5dc Stanislav Lisovskiy 2020-05-22 434 struct intel_bw_state *new_bw_state = NULL; cac91e671ad5dc Stanislav Lisovskiy 2020-05-22 435 struct intel_bw_state *old_bw_state = NULL; cd19154608610a Stanislav Lisovskiy 2020-05-20 436 const struct intel_crtc_state *crtc_state; cd19154608610a Stanislav Lisovskiy 2020-05-20 437 struct intel_crtc *crtc; cd19154608610a Stanislav Lisovskiy 2020-05-20 438 int max_bw = 0; cd19154608610a Stanislav Lisovskiy 2020-05-20 439 int slice_id; 21b0324886122a Stanislav Lisovskiy 2020-05-26 440 enum pipe pipe; cac91e671ad5dc Stanislav Lisovskiy 2020-05-22 441 int i; cd19154608610a Stanislav Lisovskiy 2020-05-20 442 cd19154608610a Stanislav Lisovskiy 2020-05-20 443 for_each_new_intel_crtc_in_state(state, crtc, crtc_state, i) { cd19154608610a Stanislav Lisovskiy 2020-05-20 444 enum plane_id plane_id; cd19154608610a Stanislav Lisovskiy 2020-05-20 445 struct intel_dbuf_bw *crtc_bw; cd19154608610a Stanislav Lisovskiy 2020-05-20 446 cd19154608610a Stanislav Lisovskiy 2020-05-20 447 new_bw_state = intel_atomic_get_bw_state(state); cd19154608610a Stanislav Lisovskiy 2020-05-20 448 if (IS_ERR(new_bw_state)) cd19154608610a Stanislav Lisovskiy 2020-05-20 449 return PTR_ERR(new_bw_state); cd19154608610a Stanislav Lisovskiy 2020-05-20 450 21b0324886122a Stanislav Lisovskiy 2020-05-26 451 old_bw_state = intel_atomic_get_old_bw_state(state); 21b0324886122a Stanislav Lisovskiy 2020-05-26 452 21b0324886122a Stanislav Lisovskiy 2020-05-26 @453 crtc_bw = &new_bw_state->dbuf_bw[pipe]; ^^^^ Not initialized. Probably "i" was intended? cd19154608610a Stanislav Lisovskiy 2020-05-20 454 cd19154608610a Stanislav Lisovskiy 2020-05-20 455 memset(&crtc_bw->used_bw, 0, sizeof(crtc_bw->used_bw)); cd19154608610a Stanislav Lisovskiy 2020-05-20 456 cd19154608610a Stanislav Lisovskiy 2020-05-20 457 for_each_plane_id_on_crtc(crtc, plane_id) { cd19154608610a Stanislav Lisovskiy 2020-05-20 458 const struct skl_ddb_entry *plane_alloc = cd19154608610a Stanislav Lisovskiy 2020-05-20 459 &crtc_state->wm.skl.plane_ddb_y[plane_id]; cd19154608610a Stanislav Lisovskiy 2020-05-20 460 const struct skl_ddb_entry *uv_plane_alloc = cd19154608610a Stanislav Lisovskiy 2020-05-20 461 &crtc_state->wm.skl.plane_ddb_uv[plane_id]; cd19154608610a Stanislav Lisovskiy 2020-05-20 462 unsigned int data_rate = crtc_state->data_rate[plane_id]; cd19154608610a Stanislav Lisovskiy 2020-05-20 463 unsigned int dbuf_mask = 0; cd19154608610a Stanislav Lisovskiy 2020-05-20 464 cd19154608610a Stanislav Lisovskiy 2020-05-20 465 dbuf_mask |= skl_ddb_dbuf_slice_mask(dev_priv, plane_alloc); cd19154608610a Stanislav Lisovskiy 2020-05-20 466 dbuf_mask |= skl_ddb_dbuf_slice_mask(dev_priv, uv_plane_alloc); cd19154608610a Stanislav Lisovskiy 2020-05-20 467 cd19154608610a Stanislav Lisovskiy 2020-05-20 468 /* cac91e671ad5dc Stanislav Lisovskiy 2020-05-22 469 * FIXME: To calculate that more properly we probably cac91e671ad5dc Stanislav Lisovskiy 2020-05-22 470 * need to to split per plane data_rate into data_rate_y cac91e671ad5dc Stanislav Lisovskiy 2020-05-22 471 * and data_rate_uv for multiplanar formats in order not cac91e671ad5dc Stanislav Lisovskiy 2020-05-22 472 * to get accounted those twice if they happen to reside cac91e671ad5dc Stanislav Lisovskiy 2020-05-22 473 * on different slices. cac91e671ad5dc Stanislav Lisovskiy 2020-05-22 474 * However for pre-icl this would work anyway because cac91e671ad5dc Stanislav Lisovskiy 2020-05-22 475 * we have only single slice and for icl+ uv plane has cac91e671ad5dc Stanislav Lisovskiy 2020-05-22 476 * non-zero data rate. cac91e671ad5dc Stanislav Lisovskiy 2020-05-22 477 * So in worst case those calculation are a bit cac91e671ad5dc Stanislav Lisovskiy 2020-05-22 478 * pessimistic, which shouldn't pose any significant cac91e671ad5dc Stanislav Lisovskiy 2020-05-22 479 * problem anyway. cd19154608610a Stanislav Lisovskiy 2020-05-20 480 */ cd19154608610a Stanislav Lisovskiy 2020-05-20 481 for_each_dbuf_slice_in_mask(slice_id, dbuf_mask) cd19154608610a Stanislav Lisovskiy 2020-05-20 482 crtc_bw->used_bw[slice_id] += data_rate; cd19154608610a Stanislav Lisovskiy 2020-05-20 483 } 21b0324886122a Stanislav Lisovskiy 2020-05-26 484 } 21b0324886122a Stanislav Lisovskiy 2020-05-26 485 21b0324886122a Stanislav Lisovskiy 2020-05-26 486 if (!old_bw_state) 21b0324886122a Stanislav Lisovskiy 2020-05-26 487 return 0; 21b0324886122a Stanislav Lisovskiy 2020-05-26 488 21b0324886122a Stanislav Lisovskiy 2020-05-26 489 for_each_pipe(dev_priv, pipe) { 21b0324886122a Stanislav Lisovskiy 2020-05-26 490 struct intel_dbuf_bw *crtc_bw; 21b0324886122a Stanislav Lisovskiy 2020-05-26 491 21b0324886122a Stanislav Lisovskiy 2020-05-26 492 crtc_bw = &new_bw_state->dbuf_bw[pipe]; cd19154608610a Stanislav Lisovskiy 2020-05-20 493 cd19154608610a Stanislav Lisovskiy 2020-05-20 494 for_each_dbuf_slice(slice_id) { cd19154608610a Stanislav Lisovskiy 2020-05-20 495 /* cac91e671ad5dc Stanislav Lisovskiy 2020-05-22 496 * Current experimental observations show that contrary cac91e671ad5dc Stanislav Lisovskiy 2020-05-22 497 * to BSpec we get underruns once we exceed 64 * CDCLK cac91e671ad5dc Stanislav Lisovskiy 2020-05-22 498 * for slices in total. cac91e671ad5dc Stanislav Lisovskiy 2020-05-22 499 * As a temporary measure in order not to keep CDCLK cac91e671ad5dc Stanislav Lisovskiy 2020-05-22 500 * bumped up all the time we calculate CDCLK according cac91e671ad5dc Stanislav Lisovskiy 2020-05-22 501 * to this formula for overall bw consumed by slices. cd19154608610a Stanislav Lisovskiy 2020-05-20 502 */ cd19154608610a Stanislav Lisovskiy 2020-05-20 503 max_bw += crtc_bw->used_bw[slice_id]; cd19154608610a Stanislav Lisovskiy 2020-05-20 504 } cd19154608610a Stanislav Lisovskiy 2020-05-20 505 } cd19154608610a Stanislav Lisovskiy 2020-05-20 506 21b0324886122a Stanislav Lisovskiy 2020-05-26 507 new_bw_state->min_cdclk = max_bw / 64; cd19154608610a Stanislav Lisovskiy 2020-05-20 508 cd19154608610a Stanislav Lisovskiy 2020-05-20 509 if (new_bw_state->min_cdclk != old_bw_state->min_cdclk) { cd19154608610a Stanislav Lisovskiy 2020-05-20 510 int ret = intel_atomic_lock_global_state(&new_bw_state->base); cd19154608610a Stanislav Lisovskiy 2020-05-20 511 cd19154608610a Stanislav Lisovskiy 2020-05-20 512 if (ret) cd19154608610a Stanislav Lisovskiy 2020-05-20 513 return ret; cd19154608610a Stanislav Lisovskiy 2020-05-20 514 } cd19154608610a Stanislav Lisovskiy 2020-05-20 515 cd19154608610a Stanislav Lisovskiy 2020-05-20 516 return 0; cd19154608610a Stanislav Lisovskiy 2020-05-20 517 } --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org