Currently, if drm.debug is enabled, we get a DRM_ERROR message on the
intermediate edid reads. This causes transient failures in CI which
flags up the sporadic EDID read failures, which are recovered by
rereading the EDID automatically. This patch combines the reporting done
by drm_do_get_edid() itself with the bad block printing from
get_edid_block(), into a single warning associated with the connector
once all attempts to retrieve the EDID fail.

v2: Print the whole EDID, marking up the bad/zero blocks. This requires
recording the whole of the raw edid, then a second pass to reduce it to
the valid extensions.
v3: Fix invalid/valid extension fumble.

References: https://bugs.freedesktop.org/show_bug.cgi?id=98228Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161024113821.26263-1-chris@chris-wilson.co.uk