On Fri, Dec 04, 2015 at 11:09:11AM +0100, Daniel Vetter wrote: > On Tue, Dec 01, 2015 at 03:08:41PM +0200, [email protected] wrote: > > From: Ville Syrjälä <[email protected]> > > > > Currently we disable some parts of FDI setup after a failed link > > training. But despite that we continue with the modeset as if everything > > is fine. This results in tons of noise from the state checker, and > > it means we're not following the proper modeset sequence for the rest of > > crtc enabling, nor for crtc disabling. > > > > Ideally we should abort the modeset and follow the proper disable > > suquenced to shut off everything we enabled so far, but that would > > require a big rework of the modeset code. So instead just leave FDI > > up and running in its untrained state, and log an error. This is > > what we do on older platforms too. > > No, ideally we should light the pipe up and tell userspace through some > uevent that something bad has happened.
That's not ideal from the hardware POV, and it's rather against the spec even. But this patch does exactly that. > Especially with async commits > failing to light up the pipe looks to userspace like the kernel just > randomly disabled it. And that usually results in random crashes when the > next flip or vblank wait fails and everything comes crashing down. And > even if we wouldn't -EINVAL these userspace would still have a problem > since the flip or vblank it wants to wait for simply never happens and > then it's just stalled. > > We've had tons of problems with this in the past, and therefore removed > all the in-kernel sources for shutting down a pipe. E.g. DP re-training > also forces the pipe to on again, even if it fails. > > Yup dp mst is an exception and I need to fix it eventually. > > Cheers, Daniel > > > > Signed-off-by: Ville Syrjälä <[email protected]> > > --- > > drivers/gpu/drm/i915/intel_ddi.c | 24 +++++++++++++++--------- > > 1 file changed, 15 insertions(+), 9 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/intel_ddi.c > > b/drivers/gpu/drm/i915/intel_ddi.c > > index 76ce7c2960b6..b312a47a0654 100644 > > --- a/drivers/gpu/drm/i915/intel_ddi.c > > +++ b/drivers/gpu/drm/i915/intel_ddi.c > > @@ -675,15 +675,16 @@ void hsw_fdi_link_train(struct drm_crtc *crtc) > > temp = I915_READ(DP_TP_STATUS(PORT_E)); > > if (temp & DP_TP_STATUS_AUTOTRAIN_DONE) { > > DRM_DEBUG_KMS("FDI link training done on step %d\n", i); > > + break; > > + } > > > > - /* Enable normal pixel sending for FDI */ > > - I915_WRITE(DP_TP_CTL(PORT_E), > > - DP_TP_CTL_FDI_AUTOTRAIN | > > - DP_TP_CTL_LINK_TRAIN_NORMAL | > > - DP_TP_CTL_ENHANCED_FRAME_ENABLE | > > - DP_TP_CTL_ENABLE); > > - > > - return; > > + /* > > + * Leave things enabled even if we failed to train FDI. > > + * Results in less fireworks from the state checker. > > + */ > > + if (i == ARRAY_SIZE(hsw_ddi_translations_fdi) * 2 - 1) { > > + DRM_ERROR("FDI link training failed!\n"); > > + break; > > } > > > > temp = I915_READ(DDI_BUF_CTL(PORT_E)); > > @@ -712,7 +713,12 @@ void hsw_fdi_link_train(struct drm_crtc *crtc) > > POSTING_READ(FDI_RX_MISC(PIPE_A)); > > } > > > > - DRM_ERROR("FDI link training failed!\n"); > > + /* Enable normal pixel sending for FDI */ > > + I915_WRITE(DP_TP_CTL(PORT_E), > > + DP_TP_CTL_FDI_AUTOTRAIN | > > + DP_TP_CTL_LINK_TRAIN_NORMAL | > > + DP_TP_CTL_ENHANCED_FRAME_ENABLE | > > + DP_TP_CTL_ENABLE); > > } > > > > void intel_ddi_init_dp_buf_reg(struct intel_encoder *encoder) > > -- > > 2.4.10 > > > > _______________________________________________ > > Intel-gfx mailing list > > [email protected] > > http://lists.freedesktop.org/mailman/listinfo/intel-gfx > > -- > Daniel Vetter > Software Engineer, Intel Corporation > http://blog.ffwll.ch -- Ville Syrjälä Intel OTC _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
