drm: make mode_valid callback optional

Many drm connectors do not need mode validation.
The patch makes this callback optional and removes dumb implementations.

v2: Rebase:
- imx move to a shared (but still dummy) ->mode_valid implementation.
- probe helpers have been extracted to drm_probe_helper.c

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com> (v1)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

18 files changed, 5 insertions, 85 deletions

diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl
index 677a02553ec0..c72e146e58d3 100644
--- a/Documentation/DocBook/drm.tmpl
+++ b/Documentation/DocBook/drm.tmpl
@@ -1903,8 +1903,8 @@ void intel_crt_init(struct drm_device *dev)
           <para>
             The function filters out modes larger than
             <parameter>max_width</parameter> and <parameter>max_height</parameter>
-            if specified. It then calls the connector
-            <methodname>mode_valid</methodname> helper operation for  each mode in
+            if specified. It then calls the optional connector
+            <methodname>mode_valid</methodname> helper operation for each mode in
             the probed list to check whether the mode is valid for the connector.
           </para>
         </listitem>
@@ -2265,7 +2265,7 @@ void intel_crt_init(struct drm_device *dev)
           <para>
             Verify whether a mode is valid for the connector. Return MODE_OK for
             supported modes and one of the enum drm_mode_status values (MODE_*)
-            for unsupported modes. This operation is mandatory.
+            for unsupported modes. This operation is optional.
           </para>
           <para>
             As the mode rejection reason is currently not used beside for
diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c
index a4afdc8bb578..e599d64a2620 100644
--- a/drivers/gpu/drm/ast/ast_mode.c
+++ b/drivers/gpu/drm/ast/ast_mode.c
@@ -743,12 +743,6 @@ static int ast_get_modes(struct drm_connector *connector)
         return 0;
 }
 
-static int ast_mode_valid(struct drm_connector *connector,
-                          struct drm_display_mode *mode)
-{
-        return MODE_OK;
-}
-
 static void ast_connector_destroy(struct drm_connector *connector)
 {
         struct ast_connector *ast_connector = to_ast_connector(connector);
@@ -765,7 +759,6 @@ ast_connector_detect(struct drm_connector *connector, bool force)
 }
 
 static const struct drm_connector_helper_funcs ast_connector_helper_funcs = {
-        .mode_valid = ast_mode_valid,
         .get_modes = ast_get_modes,
         .best_encoder = ast_best_single_encoder,
 };
diff --git a/drivers/gpu/drm/bridge/ptn3460.c b/drivers/gpu/drm/bridge/ptn3460.c
index b171901a3553..98fd17ae4916 100644
--- a/drivers/gpu/drm/bridge/ptn3460.c
+++ b/drivers/gpu/drm/bridge/ptn3460.c
@@ -225,12 +225,6 @@ out:
         return num_modes;
 }
 
-static int ptn3460_mode_valid(struct drm_connector *connector,
-                struct drm_display_mode *mode)
-{
-        return MODE_OK;
-}
-
 struct drm_encoder *ptn3460_best_encoder(struct drm_connector *connector)
 {
         struct ptn3460_bridge *ptn_bridge;
@@ -242,7 +236,6 @@ struct drm_encoder *ptn3460_best_encoder(struct drm_connector *connector)
 
 struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = {
         .get_modes = ptn3460_get_modes,
-        .mode_valid = ptn3460_mode_valid,
         .best_encoder = ptn3460_best_encoder,
 };
 
diff --git a/drivers/gpu/drm/cirrus/cirrus_mode.c b/drivers/gpu/drm/cirrus/cirrus_mode.c
index f59433b7610c..49332c5fe35b 100644
--- a/drivers/gpu/drm/cirrus/cirrus_mode.c
+++ b/drivers/gpu/drm/cirrus/cirrus_mode.c
@@ -505,13 +505,6 @@ static int cirrus_vga_get_modes(struct drm_connector *connector)
         return count;
 }
 
-static int cirrus_vga_mode_valid(struct drm_connector *connector,
-                                 struct drm_display_mode *mode)
-{
-        /* Any mode we've added is valid */
-        return MODE_OK;
-}
-
 static struct drm_encoder *cirrus_connector_best_encoder(struct drm_connector
                                                   *connector)
 {
@@ -546,7 +539,6 @@ static void cirrus_connector_destroy(struct drm_connector *connector)
 
 struct drm_connector_helper_funcs cirrus_vga_connector_helper_funcs = {
         .get_modes = cirrus_vga_get_modes,
-        .mode_valid = cirrus_vga_mode_valid,
         .best_encoder = cirrus_connector_best_encoder,
 };
 
diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c
index e70f54d4a581..d06340985a72 100644
--- a/drivers/gpu/drm/drm_probe_helper.c
+++ b/drivers/gpu/drm/drm_probe_helper.c
@@ -169,7 +169,7 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
         drm_mode_validate_flag(connector, mode_flags);
 
         list_for_each_entry(mode, &connector->modes, head) {
-                if (mode->status == MODE_OK)
+                if (mode->status == MODE_OK && connector_funcs->mode_valid)
                         mode->status = connector_funcs->mode_valid(connector,
                                                                    mode);
         }
diff --git a/drivers/gpu/drm/exynos/exynos_dp_core.c b/drivers/gpu/drm/exynos/exynos_dp_core.c
index aed533bbfd31..bb74472b4e4b 100644
--- a/drivers/gpu/drm/exynos/exynos_dp_core.c
+++ b/drivers/gpu/drm/exynos/exynos_dp_core.c
@@ -949,12 +949,6 @@ static int exynos_dp_get_modes(struct drm_connector *connector)
         return 1;
 }
 
-static int exynos_dp_mode_valid(struct drm_connector *connector,
-                        struct drm_display_mode *mode)
-{
-        return MODE_OK;
-}
-
 static struct drm_encoder *exynos_dp_best_encoder(
                         struct drm_connector *connector)
 {
@@ -965,7 +959,6 @@ static struct drm_encoder *exynos_dp_best_encoder(
 
 static struct drm_connector_helper_funcs exynos_dp_connector_helper_funcs = {
         .get_modes = exynos_dp_get_modes,
-        .mode_valid = exynos_dp_mode_valid,
         .best_encoder = exynos_dp_best_encoder,
 };
 
diff --git a/drivers/gpu/drm/exynos/exynos_drm_dpi.c b/drivers/gpu/drm/exynos/exynos_drm_dpi.c
index 2b09c7c0bfcc..82e52c71bccc 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_dpi.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dpi.c
@@ -94,12 +94,6 @@ static int exynos_dpi_get_modes(struct drm_connector *connector)
         return 0;