From 53fd40a90f3c0bdad86ec266ee5df833f54ace39 Mon Sep 17 00:00:00 2001
From: Jani Nikula <jani.nikula@intel.com>
Date: Tue, 12 Sep 2017 11:19:26 +0300
Subject: [PATCH] drm: handle override and firmware EDID at drm_do_get_edid()
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Handle debugfs override edid and firmware edid at the low level to
transparently and completely replace the real edid. Previously, we
practically only used the modes from the override EDID, and none of the
other data, such as audio parameters.
This change also prevents actual EDID reads when the EDID is to be
overridden, but retains the DDC probe. This is useful if the reason for
preferring override EDID are problems with reading the data, or
corruption of the data.
Move firmware EDID loading from helper to core, as the functionality
moves to lower level as well. This will result in a change of module
parameter from drm_kms_helper.edid_firmware to drm.edid_firmware, which
arguably makes more sense anyway.
Some future work remains related to override and firmware EDID
validation. Like before, no validation is done for override EDID. The
firmware EDID is validated separately in the loader. Some unification
and deduplication would be in order, to validate all of them at the
drm_do_get_edid() level, like "real" EDIDs.
v2: move firmware loading to core
v3: rebase, commit message refresh
Cc: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Dave Airlie <airlied@gmail.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1e8a710bcac46e5136c1a7b430074893c81f364a.1505203831.git.jani.nikula@intel.com
---
.../admin-guide/kernel-parameters.txt | 2 +-
drivers/gpu/drm/Kconfig | 2 +-
drivers/gpu/drm/Makefile | 2 +-
drivers/gpu/drm/drm_edid.c | 15 +++++++++++++++
drivers/gpu/drm/drm_probe_helper.c | 19 +------------------
5 files changed, 19 insertions(+), 21 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index d9c171ce41908..9b393c29953f2 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -854,7 +854,7 @@
The filter can be disabled or changed to another
driver later using sysfs.
- drm_kms_helper.edid_firmware=[<connector>:]<file>[,[<connector>:]<file>]
+ drm.edid_firmware=[<connector>:]<file>[,[<connector>:]<file>]
Broken monitors, graphic adapters, KVMs and EDIDless
panels may send no or incorrect EDID data sets.
This parameter allows to specify an EDID data sets
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index c5e1a84092858..c9f09fc298bb0 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -110,7 +110,7 @@ config DRM_FBDEV_OVERALLOC
config DRM_LOAD_EDID_FIRMWARE
bool "Allow to specify an EDID data set instead of probing for it"
- depends on DRM_KMS_HELPER
+ depends on DRM
help
Say Y here, if you want to use EDID data to be loaded from the
/lib/firmware directory or one of the provided built-in
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index df923119ac36a..0ee184f56a602 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -28,6 +28,7 @@ drm-$(CONFIG_DRM_PANEL) += drm_panel.o
drm-$(CONFIG_OF) += drm_of.o
drm-$(CONFIG_AGP) += drm_agpsupport.o
drm-$(CONFIG_DEBUG_FS) += drm_debugfs.o drm_debugfs_crc.o
+drm-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o
drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_probe_helper.o \
drm_plane_helper.o drm_dp_mst_topology.o drm_atomic_helper.o \
@@ -36,7 +37,6 @@ drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_probe_helper.o \
drm_scdc_helper.o drm_gem_framebuffer_helper.o
drm_kms_helper-$(CONFIG_DRM_PANEL_BRIDGE) += bridge/panel.o
-drm_kms_helper-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o
drm_kms_helper-$(CONFIG_DRM_FBDEV_EMULATION) += drm_fb_helper.o
drm_kms_helper-$(CONFIG_DRM_KMS_CMA_HELPER) += drm_fb_cma_helper.o
drm_kms_helper-$(CONFIG_DRM_DP_AUX_CHARDEV) += drm_dp_aux_dev.o
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 6bb6337be920c..00ddabfbf9804 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -1533,6 +1533,10 @@ static void connector_bad_edid(struct drm_connector *connector,
* level, drivers must make all reasonable efforts to expose it as an I2C
* adapter and use drm_get_edid() instead of abusing this function.
*
+ * The EDID may be overridden using debugfs override_edid or firmare EDID
+ * (drm_load_edid_firmware() and drm.edid_firmware parameter), in this priority
+ * order. Having either of them bypasses actual EDID reads.
+ *
* Return: Pointer to valid EDID or NULL if we couldn't find any.
*/
struct edid *drm_do_get_edid(struct drm_connector *connector,
@@ -1542,6 +1546,17 @@ struct edid *drm_do_get_edid(struct drm_connector *connector,
{
int i, j = 0, valid_extensions = 0;
u8 *edid, *new;
+ struct edid *override = NULL;
+
+ if (connector->override_edid)
+ override = drm_edid_duplicate((const struct edid *)
+ connector->edid_blob_ptr->data);
+
+ if (!override)
+ override = drm_load_edid_firmware(connector);
+
+ if (!IS_ERR_OR_NULL(override))
+ return override;
if ((edid = kmalloc(EDID_LENGTH, GFP_KERNEL)) == NULL)
return NULL;
diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c
index 904966cde32b5..5840aabbf24e5 100644
--- a/drivers/gpu/drm/drm_probe_helper.c
+++ b/drivers/gpu/drm/drm_probe_helper.c
@@ -353,8 +353,6 @@ EXPORT_SYMBOL(drm_helper_probe_detect);
* drm_mode_probed_add(). New modes start their life with status as OK.
* Modes are added from a single source using the following priority order.
*
- * - debugfs 'override_edid' (used for testing only)
- * - firmware EDID (drm_load_edid_firmware())
* - &drm_connector_helper_funcs.get_modes vfunc
* - if the connector status is connector_status_connected, standard
* VESA DMT modes up to 1024x768 are automatically added
@@ -483,22 +481,7 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
goto prune;
}
- if (connector->override_edid) {
- struct edid *edid = (struct edid *) connector->edid_blob_ptr->data;
-
- count = drm_add_edid_modes(connector, edid);
- drm_edid_to_eld(connector, edid);
- } else {
- struct edid *edid = drm_load_edid_firmware(connector);
- if (!IS_ERR_OR_NULL(edid)) {
- drm_mode_connector_update_edid_property(connector, edid);
- count = drm_add_edid_modes(connector, edid);
- drm_edid_to_eld(connector, edid);
- kfree(edid);
- }
- if (count == 0)
- count = (*connector_funcs->get_modes)(connector);
- }
+ count = (*connector_funcs->get_modes)(connector);
if (count == 0 && connector->status == connector_status_connected)
count = drm_add_modes_noedid(connector, 1024, 768);