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  1. 13 Apr, 2017 3 commits
    • Manasi Navare's avatar
      drm/i915: Implement Link Rate fallback on Link training failure · 9301397a
      Manasi Navare authored 
      If link training at a link rate optimal for a particular
mode fails during modeset's atomic commit phase, then we
let the modeset complete and then retry. We save the link rate
value at which link training failed, update the link status property
to "BAD" and use a lower link rate to prune the modes. It will redo
the modeset on the current mode at lower link rate or if the current
mode gets pruned due to lower link constraints then, it will send a
hotplug uevent for userspace to handle it.

This is also required to pass DP CTS tests 4.3.1.3, 4.3.1.4,
4.3.1.6.

This patch is a resend of the original commit id (233ce881
"drm/i915: Implement Link Rate fallback on Link training failure")
which got reverted in this commit id (afc1ebf4 Revert
"drm/i915: Implement Link Rate fallback on Link training failure")
due to CI failures.

After investigating the CI failures it was found that these
were essentially the failures which were always there but hidden because
they used to be DRM_DEBUG_KMS messages for link failures so never got
caught by CI. But now this patch actually throws DRM_ERROR if the link
training fails at RBR and 1 lane. So it caught these link train failures.

There were two failures:
1. On SKL 6700k this was because the machine in CI lab is a SKL desktop
without eDP on Port A. But our VBT initialization code in the driver writes
VBT defaults in a way that it always sets DP flag on Port A and this does
not get cleared after parsing the VBT outputs. This has been fixed in
commit id (bb1d1329 "drm/i915/vbt: split out defaults that are set
when there is no VBT) and (66578857 "drm/i915/vbt: don't propagate
errors from intel_bios_init())

2. On ILK-650 desktop - This was happening because of a bad monitor desktop
combination. I switched the monitor in the CI lab and that helped get rid
of the link failures on ILK system.

v10:
* Rebase on drm-tip and resend after revert
v9:
* Use the trimmed max values of link rate/lane count based on
link train fallback (Daniel Vetter)
v8:
* Set link_status to BAD first and then call mode_valid (Jani Nikula)
v7:
Remove the redundant variable in previous patch itself
v6:
* Obtain link rate index from fallback_link_rate using
the helper intel_dp_link_rate_index (Jani Nikula)
* Include fallback within intel_dp_start_link_train (Jani Nikula)
v5:
* Move set link status to drm core (Daniel Vetter, Jani Nikula)
v4:
* Add fallback support for non DDI platforms too
* Set connector->link status inside set_link_status function
(Jani Nikula)
v3:
* Set link status property to BAd unconditionally (Jani Nikula)
* Dont use two separate variables link_train_failed and link_status
to indicate same thing (Jani Nikula)
v2:
* Squashed a few patches (Jani Nikula)
Acked-by: default avatarTony Cheng <tony.cheng@amd.com>
Acked-by: default avatarHarry Wentland <Harry.wentland@amd.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Signed-off-by: default avatarManasi Navare <manasi.d.navare@intel.com>
Reviewed-by: default avatarJani Nikula <jani.nikula@intel.com>
Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/16ca48b1e74c618929245e9a085b9e3483c3a16d.1491485983.git.jani.nikula@intel.com
      9301397a
    • Ville Syrjälä's avatar
      drm/i915: Perform link quality check unconditionally during long pulse · 1a36147b
      Ville Syrjälä authored 
      Apparently some DP sinks are a little nuts and cause HPD to drop
intermittently during modesets. This happens eg. on an ASUS PB287Q.
In oder to recover from this we can't really use the previous
connector status to determine if the link needs retraining, so let's
just ignore that piece of information and do the retrain
unconditionally. We do of course still check whether the link is
supposed to be running or not.

To actually get read out the EDID and update things properly we
also need to nuke the goto out added by commit 7d23e3c3
("drm/i915: Cleaning up intel_dp_hpd_pulse"). I'm actually not sure
why that was there. Perhaps to avoid an EDID read if the connector
status didn't appear to change, but that sort of thing is quite racy
and would have failed anyway if we failed to keep up with the
hotplugs (if we missed the HPD down in between two HPD ups). And
now that we take this codepath unconditionally we definitely need
to drop the goto as otherwise we would never do the EDID read.

v2: Drop the goto that made us skip EDID reads entirely. Doh!
v3: Rebase due to locking changes
    s/apparely/apparently/ in the comment (Chris)

Cc: stable@vger.kernel.org
Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Reported-by: default avatarPalmer Dabbelt <palmer@dabbelt.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99766
References: https://lists.freedesktop.org/archives/intel-gfx/2017-February/119779.htmlSigned-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170412193017.21029-1-ville.syrjala@linux.intel.com
      1a36147b
    • daniele.ceraolospurio@intel.com's avatar
      drm/i915/guc: write wopcm related register once during uc init · 13f6c719
      daniele.ceraolospurio@intel.com authored 
      The wopcm registers are write-once, so any write after the first one
will just be ignored. The registers survive a GPU reset but not
always a suspend/resume cycle, so to keep things simple keep the
writes in the intel_uc_init_hw function instead of moving it earlier
to make sure we attempt them every time we try to load GuC.

Cc: Jeff McGee <jeff.mcgee@intel.com>
Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Signed-off-by: default avatarDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: default avatarJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: default avatarJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491524332-23860-1-git-send-email-daniele.ceraolospurio@intel.com
      13f6c719
  3. 12 Apr, 2017 17 commits
  5. 11 Apr, 2017 20 commits
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