On Mon, Jan 28, 2019 at 09:30:35AM +0000, Kahola, Mika wrote: > The patch look ok to me. > > On Fri, 2019-01-11 at 19:49 +0200, Ville Syrjala 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") > > Reviewed-by: Mika Kahola <mika.kahola@xxxxxxxxx> Thanks. Pushed to dinq. > > > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > --- > > 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 5dc0de89c49e..6cd6048b4731 100644 > > --- a/drivers/gpu/drm/i915/intel_display.c > > +++ b/drivers/gpu/drm/i915/intel_display.c > > @@ -15438,16 +15438,45 @@ 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_GEN(dev_priv, 6) && > > + 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) { > > @@ -15458,16 +15487,25 @@ 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; > > -- Ville Syrjälä Intel
