[Intel-gfx] [PATCH] drm/i915: Try to sanitize bogus DPLL state left over by broken SNB BIOSen
kbuild test robot
lkp at intel.com
Thu Jan 10 19:41:09 UTC 2019
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
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