drm: add helper to get crtc timings (v5)

We need to get hdisplay and vdisplay in a few places so create a
helper to make our job easier.

Note that drm_crtc_check_viewport() and intel_modeset_pipe_config() were
previously making adjustments for doublescan modes and vscan > 1 modes,
which was incorrect.  Using our new helper fixes this mistake.

v2 (by Matt): Use new stereo doubling function (suggested by Ville)

v3 (by Matt):
 - Add missing kerneldoc (Daniel)
 - Use drm_mode_copy() (Jani)

v4 (by Matt):
 - Drop stereo doubling function again; add 'stereo only' flag
   to drm_mode_set_crtcinfo() instead (Ville)

v5 (by Matt):
 - Note behavioral change in drm_crtc_check_viewport() and
   intel_modeset_pipe_config(). (Ander)
 - Describe new adjustment flags in drm_mode_set_crtcinfo()'s
   kerneldoc. (Ander)

Cc: dri-devel@lists.freedesktop.org
Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Acked-by: Dave Airlie <airlied@gmail.com>
Reviewed-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 16 insertions, 10 deletions

diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index 6d8b941c8200..7689c14f2f09 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -739,6 +739,8 @@ EXPORT_SYMBOL(drm_mode_vrefresh);
  * - The CRTC_STEREO_DOUBLE flag can be used to compute the timings for
  *   buffers containing two eyes (only adjust the timings when needed, eg. for
  *   "frame packing" or "side by side full").
+ * - The CRTC_NO_DBLSCAN and CRTC_NO_VSCAN flags request that adjustment *not*
+ *   be performed for doublescan and vscan > 1 modes respectively.
  */
 void drm_mode_set_crtcinfo(struct drm_display_mode *p, int adjust_flags)
 {
@@ -765,18 +767,22 @@ void drm_mode_set_crtcinfo(struct drm_display_mode *p, int adjust_flags)
 		}
 	}
 
-	if (p->flags & DRM_MODE_FLAG_DBLSCAN) {
-		p->crtc_vdisplay *= 2;
-		p->crtc_vsync_start *= 2;
-		p->crtc_vsync_end *= 2;
-		p->crtc_vtotal *= 2;
+	if (!(adjust_flags & CRTC_NO_DBLSCAN)) {
+		if (p->flags & DRM_MODE_FLAG_DBLSCAN) {
+			p->crtc_vdisplay *= 2;
+			p->crtc_vsync_start *= 2;
+			p->crtc_vsync_end *= 2;
+			p->crtc_vtotal *= 2;
+		}
 	}
 
-	if (p->vscan > 1) {
-		p->crtc_vdisplay *= p->vscan;
-		p->crtc_vsync_start *= p->vscan;
-		p->crtc_vsync_end *= p->vscan;
-		p->crtc_vtotal *= p->vscan;
+	if (!(adjust_flags & CRTC_NO_VSCAN)) {
+		if (p->vscan > 1) {
+			p->crtc_vdisplay *= p->vscan;
+			p->crtc_vsync_start *= p->vscan;
+			p->crtc_vsync_end *= p->vscan;
+			p->crtc_vtotal *= p->vscan;
+		}
 	}
 
 	if (adjust_flags & CRTC_STEREO_DOUBLE) {