drm/i915: Pass down rc in intel_encoder->compute_config()
authorLyude Paul <lyude@redhat.com>
Tue, 15 Jan 2019 20:08:00 +0000 (15:08 -0500)
committerJani Nikula <jani.nikula@intel.com>
Wed, 16 Jan 2019 10:49:58 +0000 (12:49 +0200)
commit204474a6b859ff2367252d8312ac65d3245823bf
treebe9a5e4702a125f675abeef2a460ee3e4a3055d7
parent9e267d286af5c5a67995128df40ca3d1f93277a6
drm/i915: Pass down rc in intel_encoder->compute_config()

Something that I completely missed when implementing the new MST VCPI
atomic helpers is that with those helpers, there's technically a chance
of us having to grab additional modeset locks in ->compute_config() and
furthermore, that means we have the potential to hit a normal modeset
deadlock. However, because ->compute_config() only returns a bool this
means we can't return -EDEADLK when we need to drop locks and try again
which means we end up just failing the atomic check permanently. Whoops.

So, fix this by modifying ->compute_config() to pass down an actual
error code instead of a bool so that the atomic check can be restarted
on modeset deadlocks.

Thanks to Ville Syrjälä for pointing this out!

Changes since v1:
* Add some newlines
* Return only -EINVAL from hsw_crt_compute_config()
* Propogate return code from intel_dp_compute_dsc_params()
* Change all of the intel_dp_compute_link_config*() variants
* Don't miss if (hdmi_port_clock_valid()) branch in
  intel_hdmi_compute_config()

[Cherry-picked from drm-misc-next to drm-intel-next-queued to fix
 linux-next & drm-tip conflict, while waiting for proper propagation of
 the DP MST series that this commit fixes. In hindsight, a topic branch
 might have been a better approach for it.]

Signed-off-by: Lyude Paul <lyude@redhat.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Fixes: eceae1472467 ("drm/dp_mst: Start tracking per-port VCPI allocations")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109320
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190115200800.3121-1-lyude@redhat.com
(cherry picked from commit 96550555a78ca3c9fda4b358549a5622810fe32c)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
13 files changed:
drivers/gpu/drm/i915/icl_dsi.c
drivers/gpu/drm/i915/intel_crt.c
drivers/gpu/drm/i915/intel_ddi.c
drivers/gpu/drm/i915/intel_display.c
drivers/gpu/drm/i915/intel_dp.c
drivers/gpu/drm/i915/intel_dp_mst.c
drivers/gpu/drm/i915/intel_drv.h
drivers/gpu/drm/i915/intel_dvo.c
drivers/gpu/drm/i915/intel_hdmi.c
drivers/gpu/drm/i915/intel_lvds.c
drivers/gpu/drm/i915/intel_sdvo.c
drivers/gpu/drm/i915/intel_tv.c
drivers/gpu/drm/i915/vlv_dsi.c