Depending on the SDVO output_flags SDVO may have multiple connectors
linking to the same encoder (in intel_connector->encoder->base).
Only one of those connectors should be active (ie link to the encoder
thru drm_connector->encoder).
If intel_connector_break_all_links() is called from intel_sanitize_crtc()
we may break the crtc connection of an encoder thru an inactive connector
in which case intel_connector_break_all_links() will not be called again
for the active connector if this happens to come later in the list due to:
if (connector->encoder->base.crtc != &crtc->base)
continue;
in intel_sanitize_crtc().
This will however leave the drm_connector->encoder linkage for this
active connector in place. Subsequently this will cause multiple
warnings in intel_connector_check_state() to trigger and the driver
will eventually die in drm_encoder_crtc_ok() (because of crtc == NULL).
To avoid this remove intel_connector_break_all_links() and move its
code to its two calling functions: intel_sanitize_crtc() and
intel_sanitize_encoder().
This allows to implement the link breaking more flexibly matching
the surrounding code: ie. in intel_sanitize_crtc() we can break the
crtc link separatly after the links to the encoders have been
broken which avoids above problem.
This regression has been introduced in:
commit 2492935248
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Mon Jul 2 20:28:59 2012 +0200
drm/i915: read out the modeset hw state at load and resume time
so goes back to the very beginning of the modeset rework.
v2: This patch takes care of the concernes voiced by Chris Wilson
and Daniel Vetter that only breaking links if the drm_connector
is linked to an encoder may miss some links.
v3: move all encoder handling to encoder loop as suggested by
Daniel Vetter.
Signed-off-by: Egbert Eich <eich@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
7f1950fbb9