From c533b5167c7e40e82dd724f2a0ffa691f7f386d2 Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Thu, 19 Jan 2023 18:18:56 +0200 Subject: [PATCH] drm/edid: add separate drm_edid_connector_add_modes() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 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 Cc: Ville Syrjälä Reviewed-by: Ville Syrjälä Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/e86fff1579f14ebf6334692526c8f6831cd02cac.1674144945.git.jani.nikula@intel.com --- drivers/gpu/drm/drm_edid.c | 44 +++++++++++++++++++++++++++++--------- drivers/gpu/drm/drm_probe_helper.c | 4 +++- include/drm/drm_edid.h | 2 ++ 3 files changed, 39 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index f9502df..d0c21d2 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -6735,30 +6735,54 @@ out: * @connector: Connector * @drm_edid: EDID * - * Update the connector mode list, display info, ELD, HDR metadata, relevant - * properties, etc. from the passed in EDID. + * Update the connector display info, ELD, HDR metadata, relevant properties, + * etc. from the passed in EDID. * * If EDID is NULL, reset the information. * - * Return: The number of modes added or 0 if we couldn't find any. + * Must be called before calling drm_edid_connector_add_modes(). + * + * Return: 0 on success, negative error on errors. */ int drm_edid_connector_update(struct drm_connector *connector, const struct drm_edid *drm_edid) { + update_display_info(connector, drm_edid); + + _drm_update_tile_info(connector, drm_edid); + + return _drm_edid_connector_property_update(connector, drm_edid); +} +EXPORT_SYMBOL(drm_edid_connector_update); + +/** + * drm_edid_connector_add_modes - Update probed modes from the EDID property + * @connector: Connector + * + * Add the modes from the previously updated EDID property to the connector + * probed modes list. + * + * drm_edid_connector_update() must have been called before this to update the + * EDID property. + * + * Return: The number of modes added, or 0 if we couldn't find any. + */ +int drm_edid_connector_add_modes(struct drm_connector *connector) +{ + const struct drm_edid *drm_edid = NULL; int count; - update_display_info(connector, drm_edid); + if (connector->edid_blob_ptr) + drm_edid = drm_edid_alloc(connector->edid_blob_ptr->data, + connector->edid_blob_ptr->length); count = _drm_edid_connector_add_modes(connector, drm_edid); - _drm_update_tile_info(connector, drm_edid); - - /* Note: Ignore errors for now. */ - _drm_edid_connector_property_update(connector, drm_edid); + drm_edid_free(drm_edid); return count; } -EXPORT_SYMBOL(drm_edid_connector_update); +EXPORT_SYMBOL(drm_edid_connector_add_modes); static int _drm_connector_update_edid_property(struct drm_connector *connector, const struct drm_edid *drm_edid) @@ -6813,7 +6837,7 @@ EXPORT_SYMBOL(drm_connector_update_edid_property); * &drm_display_info structure and ELD in @connector with any information which * can be derived from the edid. * - * This function is deprecated. Use drm_edid_connector_update() instead. + * This function is deprecated. Use drm_edid_connector_add_modes() instead. * * Return: The number of modes added or 0 if we couldn't find any. */ diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c index 7973f25..95aeeed 100644 --- a/drivers/gpu/drm/drm_probe_helper.c +++ b/drivers/gpu/drm/drm_probe_helper.c @@ -1163,7 +1163,9 @@ int drm_connector_helper_get_modes(struct drm_connector *connector) * EDID. Otherwise, if the EDID is NULL, clear the connector * information. */ - count = drm_edid_connector_update(connector, drm_edid); + drm_edid_connector_update(connector, drm_edid); + + count = drm_edid_connector_add_modes(connector); drm_edid_free(drm_edid); diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h index 3729636..70ae6c2 100644 --- a/include/drm/drm_edid.h +++ b/include/drm/drm_edid.h @@ -609,6 +609,8 @@ const struct drm_edid *drm_edid_read_custom(struct drm_connector *connector, void *context); int drm_edid_connector_update(struct drm_connector *connector, const struct drm_edid *edid); +int drm_edid_connector_add_modes(struct drm_connector *connector); + const u8 *drm_find_edid_extension(const struct drm_edid *drm_edid, int ext_id, int *ext_index); -- 2.7.4