[PATCH 3/7] drm/edid: Allow drm_mode_find_dmt to hunt for reduced-blanking modes

[Adam Jackson <ajax@redhat.com>]

It won't find any, yet.  Fix up callers to match: standard mode codes
will look prefer r-b modes for a given size if present, EST3 mode codes
will look for exactly the r-b-ness mentioned in the mode code.  This
might mean fewer modes matched for EST3 mode codes between now and when
the DMT mode list regrows the r-b modes, but practically speaking EST3
codes don't exist in the wild.

Signed-off-by: Adam Jackson <ajax@redhat.com>
---
 drivers/gpu/drm/drm_edid.c      |   37 ++++++++++++++++++++++++-------------
 drivers/gpu/drm/drm_fb_helper.c |    2 +-
 include/drm/drm_crtc.h          |    3 ++-
 3 files changed, 27 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 0a23ee5..4f52103 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -486,18 +486,29 @@ static void edid_fixup_preferred(struct drm_connector *connector,
 	preferred_mode->type |= DRM_MODE_TYPE_PREFERRED;
 }
 
+static bool
+mode_is_rb(const struct drm_display_mode *mode)
+{
+	return (mode->htotal - mode->hdisplay == 160) &&
+	       (mode->hsync_end - mode->hdisplay == 80) &&
+	       (mode->hsync_end - mode->hsync_start == 32) &&
+	       (mode->vsync_start - mode->vdisplay == 3);
+}
+
 /*
  * drm_mode_find_dmt - Create a copy of a mode if present in DMT
  * @dev: Device to duplicate against
  * @hsize: Mode width
  * @vsize: Mode height
  * @fresh: Mode refresh rate
+ * @rb: Mode reduced-blanking-ness
  *
  * Walk the DMT mode list looking for a match for the given parameters.
  * Return a newly allocated copy of the mode, or NULL if not found.
  */
 struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev,
-					   int hsize, int vsize, int fresh)
+					   int hsize, int vsize, int fresh,
+					   bool rb)
 {
 	int i;
 
@@ -509,6 +520,8 @@ struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev,
 			continue;
 		if (fresh != drm_mode_vrefresh(ptr))
 			continue;
+		if (rb != mode_is_rb(ptr))
+			continue;
 
 		return drm_mode_duplicate(dev, ptr);
 	}
@@ -742,10 +755,17 @@ drm_mode_std(struct drm_connector *connector, struct edid *edid,
 	}
 
 	/* check whether it can be found in default mode table */
-	mode = drm_mode_find_dmt(dev, hsize, vsize, vrefresh_rate);
+	if (drm_monitor_supports_rb(edid)) {
+		mode = drm_mode_find_dmt(dev, hsize, vsize, vrefresh_rate,
+					 true);
+		if (mode)
+			return mode;
+	}
+	mode = drm_mode_find_dmt(dev, hsize, vsize, vrefresh_rate, false);
 	if (mode)
 		return mode;
 
+	/* okay, generate it */
 	switch (timing_level) {
 	case LEVEL_DMT:
 		break;
@@ -920,15 +940,6 @@ static struct drm_display_mode *drm_mode_detailed(struct drm_device *dev,
 }
 
 static bool
-mode_is_rb(const struct drm_display_mode *mode)
-{
-	return (mode->htotal - mode->hdisplay == 160) &&
-	       (mode->hsync_end - mode->hdisplay == 80) &&
-	       (mode->hsync_end - mode->hsync_start == 32) &&
-	       (mode->vsync_start - mode->vdisplay == 3);
-}
-
-static bool
 mode_in_hsync_range(const struct drm_display_mode *mode,
 		    struct edid *edid, u8 *t)
 {
@@ -1073,8 +1084,8 @@ drm_est3_modes(struct drm_connector *connector, struct detailed_timing *timing)
 				mode = drm_mode_find_dmt(connector->dev,
 							 est3_modes[m].w,
 							 est3_modes[m].h,
-							 est3_modes[m].r
-							 /*, est3_modes[m].rb */);
+							 est3_modes[m].r,
+							 est3_modes[m].rb);
 				if (mode) {
 					drm_mode_probed_add(connector, mode);
 					modes++;
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index a0d6e89..6e19dd1 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1083,7 +1083,7 @@ static bool drm_target_cloned(struct drm_fb_helper *fb_helper,
 
 	/* try and find a 1024x768 mode on each connector */
 	can_clone = true;
-	dmt_mode = drm_mode_find_dmt(fb_helper->dev, 1024, 768, 60);
+	dmt_mode = drm_mode_find_dmt(fb_helper->dev, 1024, 768, 60, false);
 
 	for (i = 0; i < fb_helper->connector_count; i++) {
 
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index e250eda..2be73d7 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -1015,7 +1015,8 @@ extern int drm_edid_header_is_valid(const u8 *raw_edid);
 extern bool drm_edid_block_valid(u8 *raw_edid);
 extern bool drm_edid_is_valid(struct edid *edid);
 struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev,
-					   int hsize, int vsize, int fresh);
+					   int hsize, int vsize, int fresh,
+					   bool rb);
 
 extern int drm_mode_create_dumb_ioctl(struct drm_device *dev,
 				      void *data, struct drm_file *file_priv);
-- 
1.7.7.6