Hi Ville, Thank you for the patch! Perhaps something to improve:
url: https://github.com/0day-ci/linux/commits/Ville-Syrjala/drm-i915-Try-to-sanitize-bogus-DPLL-state-left-over-by-broken-SNB-BIOSen/20190109-222838 base: git://anongit.freedesktop.org/drm-intel for-linux-next New smatch warnings: drivers/gpu/drm/i915/intel_display.c:15452 has_bogus_dpll_config() warn: variable dereferenced before check 'crtc_state' (see line 15439) drivers/gpu/drm/i915/intel_display.c:15472 intel_sanitize_encoder() error: we previously assumed 'crtc_state' could be null (see line 15469) drivers/gpu/drm/i915/intel_display.c:15487 intel_sanitize_encoder() warn: variable dereferenced before check 'crtc_state' (see line 15472) # https://github.com/0day-ci/linux/commit/5a0056f774727561e522ccde5fe7fe78d343d25f git remote add linux-review https://github.com/0day-ci/linux git remote update linux-review git checkout 5a0056f774727561e522ccde5fe7fe78d343d25f vim +/crtc_state +15452 drivers/gpu/drm/i915/intel_display.c 249293524 Daniel Vetter 2012-07-02 15436 5a0056f77 Ville Syrjälä 2019-01-09 15437 static bool has_bogus_dpll_config(struct intel_crtc_state *crtc_state) 5a0056f77 Ville Syrjälä 2019-01-09 15438 { 5a0056f77 Ville Syrjälä 2019-01-09 @15439 struct drm_i915_private *dev_priv = to_i915(crtc_state->base.crtc->dev); 5a0056f77 Ville Syrjälä 2019-01-09 15440 5a0056f77 Ville Syrjälä 2019-01-09 15441 /* 5a0056f77 Ville Syrjälä 2019-01-09 15442 * Some SNB BIOSen (eg. ASUS K53SV) are known to misprogram 5a0056f77 Ville Syrjälä 2019-01-09 15443 * the hardware when a high res displays plugged in. DPLL P 5a0056f77 Ville Syrjälä 2019-01-09 15444 * divider is zero, and the pipe timings are bonkers. We'll 5a0056f77 Ville Syrjälä 2019-01-09 15445 * try to disable everything in that case. 5a0056f77 Ville Syrjälä 2019-01-09 15446 * 5a0056f77 Ville Syrjälä 2019-01-09 15447 * FIXME would be nice to be able to sanitize this state 5a0056f77 Ville Syrjälä 2019-01-09 15448 * without several WARNs, but for now let's take the easy 5a0056f77 Ville Syrjälä 2019-01-09 15449 * road. 5a0056f77 Ville Syrjälä 2019-01-09 15450 */ 5a0056f77 Ville Syrjälä 2019-01-09 15451 return IS_GEN(dev_priv, 6) && 5a0056f77 Ville Syrjälä 2019-01-09 @15452 crtc_state && 5a0056f77 Ville Syrjälä 2019-01-09 15453 crtc_state->base.active && 5a0056f77 Ville Syrjälä 2019-01-09 15454 crtc_state->shared_dpll && 5a0056f77 Ville Syrjälä 2019-01-09 15455 crtc_state->port_clock == 0; 5a0056f77 Ville Syrjälä 2019-01-09 15456 } 5a0056f77 Ville Syrjälä 2019-01-09 15457 249293524 Daniel Vetter 2012-07-02 15458 static void intel_sanitize_encoder(struct intel_encoder *encoder) 249293524 Daniel Vetter 2012-07-02 15459 { 70332ac53 Imre Deak 2018-11-01 15460 struct drm_i915_private *dev_priv = to_i915(encoder->base.dev); 249293524 Daniel Vetter 2012-07-02 15461 struct intel_connector *connector; 5a0056f77 Ville Syrjälä 2019-01-09 15462 struct intel_crtc *crtc = to_intel_crtc(encoder->base.crtc); 5a0056f77 Ville Syrjälä 2019-01-09 15463 struct intel_crtc_state *crtc_state = crtc ? 5a0056f77 Ville Syrjälä 2019-01-09 15464 to_intel_crtc_state(crtc->base.state) : NULL; 249293524 Daniel Vetter 2012-07-02 15465 249293524 Daniel Vetter 2012-07-02 15466 /* We need to check both for a crtc link (meaning that the 249293524 Daniel Vetter 2012-07-02 15467 * encoder is active and trying to read from a pipe) and the 249293524 Daniel Vetter 2012-07-02 15468 * pipe itself being active. */ 5a0056f77 Ville Syrjälä 2019-01-09 @15469 bool has_active_crtc = crtc_state && 5a0056f77 Ville Syrjälä 2019-01-09 15470 crtc_state->base.active; 5a0056f77 Ville Syrjälä 2019-01-09 15471 5a0056f77 Ville Syrjälä 2019-01-09 @15472 if (has_bogus_dpll_config(crtc_state)) { 5a0056f77 Ville Syrjälä 2019-01-09 15473 DRM_DEBUG_KMS("BIOS has misprogrammed the hardware. Disabling pipe %c\n", 5a0056f77 Ville Syrjälä 2019-01-09 15474 pipe_name(crtc->pipe)); 5a0056f77 Ville Syrjälä 2019-01-09 15475 has_active_crtc = false; 5a0056f77 Ville Syrjälä 2019-01-09 15476 } 249293524 Daniel Vetter 2012-07-02 15477 496b0fc37 Maarten Lankhorst 2016-08-23 15478 connector = intel_encoder_find_connector(encoder); 496b0fc37 Maarten Lankhorst 2016-08-23 15479 if (connector && !has_active_crtc) { 249293524 Daniel Vetter 2012-07-02 15480 DRM_DEBUG_KMS("[ENCODER:%d:%s] has active connectors but no active pipe!\n", 249293524 Daniel Vetter 2012-07-02 15481 encoder->base.base.id, 8e329a039 Jani Nikula 2014-06-03 15482 encoder->base.name); 249293524 Daniel Vetter 2012-07-02 15483 249293524 Daniel Vetter 2012-07-02 15484 /* Connector is active, but has no active pipe. This is 249293524 Daniel Vetter 2012-07-02 15485 * fallout from our resume register restoring. Disable 249293524 Daniel Vetter 2012-07-02 15486 * the encoder manually again. */ 5a0056f77 Ville Syrjälä 2019-01-09 @15487 if (crtc_state) { 5a0056f77 Ville Syrjälä 2019-01-09 15488 struct drm_encoder *best_encoder; fd6bbda9c Maarten Lankhorst 2016-08-09 15489 249293524 Daniel Vetter 2012-07-02 15490 DRM_DEBUG_KMS("[ENCODER:%d:%s] manually disabled\n", 249293524 Daniel Vetter 2012-07-02 15491 encoder->base.base.id, 8e329a039 Jani Nikula 2014-06-03 15492 encoder->base.name); 5a0056f77 Ville Syrjälä 2019-01-09 15493 5a0056f77 Ville Syrjälä 2019-01-09 15494 /* avoid oopsing in case the hooks consult best_encoder */ 5a0056f77 Ville Syrjälä 2019-01-09 15495 best_encoder = connector->base.state->best_encoder; 5a0056f77 Ville Syrjälä 2019-01-09 15496 connector->base.state->best_encoder = &encoder->base; 5a0056f77 Ville Syrjälä 2019-01-09 15497 c84c6fe30 Jani Nikula 2018-10-16 15498 if (encoder->disable) 5a0056f77 Ville Syrjälä 2019-01-09 15499 encoder->disable(encoder, crtc_state, 5a0056f77 Ville Syrjälä 2019-01-09 15500 connector->base.state); a62d14975 Ville Syrjälä 2014-06-28 15501 if (encoder->post_disable) 5a0056f77 Ville Syrjälä 2019-01-09 15502 encoder->post_disable(encoder, crtc_state, 5a0056f77 Ville Syrjälä 2019-01-09 15503 connector->base.state); 5a0056f77 Ville Syrjälä 2019-01-09 15504 5a0056f77 Ville Syrjälä 2019-01-09 15505 connector->base.state->best_encoder = best_encoder; 249293524 Daniel Vetter 2012-07-02 15506 } 7f1950fbb Egbert Eich 2014-04-25 15507 encoder->base.crtc = NULL; 249293524 Daniel Vetter 2012-07-02 15508 249293524 Daniel Vetter 2012-07-02 15509 /* Inconsistent output/port/pipe state happens presumably due to 249293524 Daniel Vetter 2012-07-02 15510 * a bug in one of the get_hw_state functions. Or someplace else 249293524 Daniel Vetter 2012-07-02 15511 * in our code, like the register restore mess on resume. Clamp 249293524 Daniel Vetter 2012-07-02 15512 * things to off as a safer default. */ fd6bbda9c Maarten Lankhorst 2016-08-09 15513 7f1950fbb Egbert Eich 2014-04-25 15514 connector->base.dpms = DRM_MODE_DPMS_OFF; 7f1950fbb Egbert Eich 2014-04-25 15515 connector->base.encoder = NULL; 249293524 Daniel Vetter 2012-07-02 15516 } d6cae4aa3 Maarten Lankhorst 2018-05-16 15517 d6cae4aa3 Maarten Lankhorst 2018-05-16 15518 /* notify opregion of the sanitized encoder state */ d6cae4aa3 Maarten Lankhorst 2018-05-16 15519 intel_opregion_notify_encoder(encoder, connector && has_active_crtc); 70332ac53 Imre Deak 2018-11-01 15520 70332ac53 Imre Deak 2018-11-01 15521 if (INTEL_GEN(dev_priv) >= 11) 70332ac53 Imre Deak 2018-11-01 15522 icl_sanitize_encoder_pll_mapping(encoder); 249293524 Daniel Vetter 2012-07-02 15523 } 249293524 Daniel Vetter 2012-07-02 15524 --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
