On Tue, 05 Feb 2019, Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx> wrote: > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > Certain SNB machines (eg. ASUS K53SV) seem to have a broken BIOS > which misprograms the hardware badly when encountering a suitably > high resolution display. The programmed pipe timings are somewhat > bonkers and the DPLL is totally misprogrammed (P divider == 0). > That will result in atomic commit timeouts as apparently the pipe > is sufficiently stuck to not signal vblank interrupts. > > IIRC something like this was also observed on some other SNB > machine years ago (might have been a Dell XPS 8300) but a BIOS > update cured it. Sadly looks like this was never fixed for the > ASUS K53SV as the latest BIOS (K53SV.320 11/11/2011) is still > broken. > > The quickest way to deal with this seems to be to shut down > the pipe+ports+DPLL. Unfortunately doing this during the > normal sanitization phase isn't quite soon enough as we > already spew several WARNs about the bogus hardware state. > But it's better than hanging the boot for a few dozen seconds. > Since this is limited to a few old machines it doesn't seem > entirely worthwile to try and rework the readout+sanitization > code to handle it more gracefully. > > v2: Fix potential NULL deref (kbuild test robot) > Constify has_bogus_dpll_config() > > Cc: stable@xxxxxxxxxxxxxxx # v4.20+ > Cc: Daniel Kamil Kozar <dkk089@xxxxxxxxx> > Reported-by: Daniel Kamil Kozar <dkk089@xxxxxxxxx> > Tested-by: Daniel Kamil Kozar <dkk089@xxxxxxxxx> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109245 > Fixes: 516a49cc1946 ("drm/i915: Fix assert_plane() warning on bootup with external display") > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > Link: https://patchwork.freedesktop.org/patch/msgid/20190111174950.10681-1-ville.syrjala@xxxxxxxxxxxxxxx > Reviewed-by: Mika Kahola <mika.kahola@xxxxxxxxx> > (cherry picked from commit 7bed8adcd9f86231bb69bbc02f88ad89330f99e3) Pushed to drm-intel-fixes, thanks. BR, Jani. > --- > drivers/gpu/drm/i915/intel_display.c | 50 ++++++++++++++++++++++++---- > 1 file changed, 44 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c > index 3da9c0f9e948..248128126422 100644 > --- a/drivers/gpu/drm/i915/intel_display.c > +++ b/drivers/gpu/drm/i915/intel_display.c > @@ -15415,16 +15415,45 @@ static void intel_sanitize_crtc(struct intel_crtc *crtc, > } > } > > +static bool has_bogus_dpll_config(const struct intel_crtc_state *crtc_state) > +{ > + struct drm_i915_private *dev_priv = to_i915(crtc_state->base.crtc->dev); > + > + /* > + * Some SNB BIOSen (eg. ASUS K53SV) are known to misprogram > + * the hardware when a high res displays plugged in. DPLL P > + * divider is zero, and the pipe timings are bonkers. We'll > + * try to disable everything in that case. > + * > + * FIXME would be nice to be able to sanitize this state > + * without several WARNs, but for now let's take the easy > + * road. > + */ > + return IS_GEN6(dev_priv) && > + crtc_state->base.active && > + crtc_state->shared_dpll && > + crtc_state->port_clock == 0; > +} > + > static void intel_sanitize_encoder(struct intel_encoder *encoder) > { > struct drm_i915_private *dev_priv = to_i915(encoder->base.dev); > struct intel_connector *connector; > + struct intel_crtc *crtc = to_intel_crtc(encoder->base.crtc); > + struct intel_crtc_state *crtc_state = crtc ? > + to_intel_crtc_state(crtc->base.state) : NULL; > > /* We need to check both for a crtc link (meaning that the > * encoder is active and trying to read from a pipe) and the > * pipe itself being active. */ > - bool has_active_crtc = encoder->base.crtc && > - to_intel_crtc(encoder->base.crtc)->active; > + bool has_active_crtc = crtc_state && > + crtc_state->base.active; > + > + if (crtc_state && has_bogus_dpll_config(crtc_state)) { > + DRM_DEBUG_KMS("BIOS has misprogrammed the hardware. Disabling pipe %c\n", > + pipe_name(crtc->pipe)); > + has_active_crtc = false; > + } > > connector = intel_encoder_find_connector(encoder); > if (connector && !has_active_crtc) { > @@ -15435,16 +15464,25 @@ static void intel_sanitize_encoder(struct intel_encoder *encoder) > /* Connector is active, but has no active pipe. This is > * fallout from our resume register restoring. Disable > * the encoder manually again. */ > - if (encoder->base.crtc) { > - struct drm_crtc_state *crtc_state = encoder->base.crtc->state; > + if (crtc_state) { > + struct drm_encoder *best_encoder; > > DRM_DEBUG_KMS("[ENCODER:%d:%s] manually disabled\n", > encoder->base.base.id, > encoder->base.name); > + > + /* avoid oopsing in case the hooks consult best_encoder */ > + best_encoder = connector->base.state->best_encoder; > + connector->base.state->best_encoder = &encoder->base; > + > if (encoder->disable) > - encoder->disable(encoder, to_intel_crtc_state(crtc_state), connector->base.state); > + encoder->disable(encoder, crtc_state, > + connector->base.state); > if (encoder->post_disable) > - encoder->post_disable(encoder, to_intel_crtc_state(crtc_state), connector->base.state); > + encoder->post_disable(encoder, crtc_state, > + connector->base.state); > + > + connector->base.state->best_encoder = best_encoder; > } > encoder->base.crtc = NULL; -- Jani Nikula, Intel Open Source Graphics Center
