[PATCH/RFC,029/390] drm/edid: Add a workaround for 1366x768 HD panel

Commit Message

Simon Horman March 29, 2013, 2:39 a.m. UTC

From: Takashi Iwai <[e-mail]>

HD panel (1366x768) found most commonly on laptops can't be represented
exactly in CVT/DMT expression, which leads to 1368x768 instead, because
1366 can't be divided by 8.

Add a hack to convert to 1366x768 manually as an exception.

Signed-off-by: Takashi Iwai <[e-mail]>
Acked-by: Adam Jackson <[e-mail]>
Signed-off-by: Dave Airlie <[e-mail]>
(cherry picked from commit c09dedb7a50e23f0166e0bbae61c75c7ec23cf7f)

Signed-off-by: Simon Horman <[e-mail]>
---
 drivers/gpu/drm/drm_edid.c |   15 +++++++++++++++
 1 file changed, 15 insertions(+)

Patch

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index e8ef017..261b766 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -1039,6 +1039,19 @@  drm_dmt_modes_for_range(struct drm_connector *connector, struct edid *edid,
 	return modes;
 }
 
+/* fix up 1366x768 mode from 1368x768;
+ * GFT/CVT can't express 1366 width which isn't dividable by 8
+ */
+static void fixup_mode_1366x768(struct drm_display_mode *mode)
+{
+	if (mode->hdisplay == 1368 && mode->vdisplay == 768) {
+		mode->hdisplay = 1366;
+		mode->hsync_start--;
+		mode->hsync_end--;
+		drm_mode_set_name(mode);
+	}
+}
+
 static int
 drm_gtf_modes_for_range(struct drm_connector *connector, struct edid *edid,
 			struct detailed_timing *timing)
@@ -1053,6 +1066,7 @@  drm_gtf_modes_for_range(struct drm_connector *connector, struct edid *edid,
 		if (!newmode)
 			return modes;
 
+		fixup_mode_1366x768(newmode);
 		if (!mode_in_range(newmode, edid, timing)) {
 			drm_mode_destroy(dev, newmode);
 			continue;
@@ -1080,6 +1094,7 @@  drm_cvt_modes_for_range(struct drm_connector *connector, struct edid *edid,
 		if (!newmode)
 			return modes;
 
+		fixup_mode_1366x768(newmode);
 		if (!mode_in_range(newmode, edid, timing)) {
 			drm_mode_destroy(dev, newmode);
 			continue;