drm/edid: add separate drm_edid_connector_add_modes()
The original goal with drm_edid_connector_update() was to have a single call for updating the connector and adding probed modes, in this order, but that turned out to be problematic. Drivers that need to update the connector in the .detect() callback would end up updating the probed modes as well. Turns out the callback may be called so many times that the probed mode list fills up without bounds, and this is amplified by add_alternate_cea_modes() duplicating the CEA modes on every call, actually running out of memory on some machines. Kudos to Imre Deak <imre.deak@intel.com> for explaining this to me. Go back to having separate drm_edid_connector_update() and drm_edid_connector_add_modes() calls. The former may be called from .detect(), .force(), or .get_modes(), but the latter only from .get_modes(). Unlike drm_add_edid_modes(), have drm_edid_connector_add_modes() update the probed modes from the EDID property instead of the passed in EDID. This is mainly to enforce two things: 1) drm_edid_connector_update() must be called before drm_edid_connector_add_modes(). Display info and quirks are needed for parsing the modes, and we don't want to call update_display_info() again to ensure the info is available, like drm_add_edid_modes() does. 2) The same EDID is used for both updating the connector and adding the probed modes. Fortunately, the change is easy, because no driver has actually adopted drm_edid_connector_update(). Not even i915, and that's mainly because of the problem described above. Cc: Imre Deak <imre.deak@intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/e86fff1579f14ebf6334692526c8f6831cd02cac.1674144945.git.jani.nikula@intel.com