drm: Clean up the 1366x768 fixup codes

This is just a cleanup, no functional change.

The fixup code for 1366x768 in drm_mode_create_from_cmdline_mode() is
basically a copy of the existing code in drm_edid.c.  Make the latter
code public so that it can be called from the former function.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: http://patchwork.freedesktop.org/patch/msgid/20170117164329.10551-1-tiwai@suse.de
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
[vsyrjala: include drm_crtc_internal.h to make sparse happy]
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

drivers/gpu/drm/drm_crtc_internal.h

@@ -207,3 +207,6 @@ int drm_mode_cursor2_ioctl(struct drm_device *dev,
 			   void *data, struct drm_file *file_priv);
 int drm_mode_page_flip_ioctl(struct drm_device *dev,
 			     void *data, struct drm_file *file_priv);
+
+/* drm_edid.c */
+void drm_mode_fixup_1366x768(struct drm_display_mode *mode);

drivers/gpu/drm/drm_edid.c

@@ -38,6 +38,8 @@
 #include <drm/drm_encoder.h>
 #include <drm/drm_displayid.h>
 
+#include "drm_crtc_internal.h"
+
 #define version_greater(edid, maj, min) \
 	(((edid)->version > (maj)) || \
 	 ((edid)->version == (maj) && (edid)->revision > (min)))
@@ -2153,7 +2155,7 @@ drm_dmt_modes_for_range(struct drm_connector *connector, struct edid *edid,
 /* 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)
+void drm_mode_fixup_1366x768(struct drm_display_mode *mode)
 {
 	if (mode->hdisplay == 1368 && mode->vdisplay == 768) {
 		mode->hdisplay = 1366;
@@ -2177,7 +2179,7 @@ drm_gtf_modes_for_range(struct drm_connector *connector, struct edid *edid,
 		if (!newmode)
 			return modes;
 
-		fixup_mode_1366x768(newmode);
+		drm_mode_fixup_1366x768(newmode);
 		if (!mode_in_range(newmode, edid, timing) ||
 		    !valid_inferred_mode(connector, newmode)) {
 			drm_mode_destroy(dev, newmode);
@@ -2206,7 +2208,7 @@ drm_cvt_modes_for_range(struct drm_connector *connector, struct edid *edid,
 		if (!newmode)
 			return modes;
 
-		fixup_mode_1366x768(newmode);
+		drm_mode_fixup_1366x768(newmode);
 		if (!mode_in_range(newmode, edid, timing) ||
 		    !valid_inferred_mode(connector, newmode)) {
 			drm_mode_destroy(dev, newmode);

drivers/gpu/drm/drm_modes.c

@@ -1481,12 +1481,8 @@ drm_mode_create_from_cmdline_mode(struct drm_device *dev,
 
 	mode->type |= DRM_MODE_TYPE_USERDEF;
 	/* fix up 1368x768: GFT/CVT can't express 1366 width due to alignment */
-	if (cmd->xres == 1366 && mode->hdisplay == 1368) {
-		mode->hdisplay = 1366;
-		mode->hsync_start--;
-		mode->hsync_end--;
-		drm_mode_set_name(mode);
-	}
+	if (cmd->xres == 1366)
+		drm_mode_fixup_1366x768(mode);
 	drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
 	return mode;
 }