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authorLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>2018-11-11 03:15:08 +0100
committerLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>2018-11-23 12:51:23 +0100
commit256856efb8cc2b5468c69edf45eb0ab579833ce7 (patch)
tree255ab951272ed61859b9e3fa1aa1b232c24835c3 /drivers/gpu/drm/rcar-du
parentdrm: rcar-du: Fix external clock error checks (diff)
downloadlinux-256856efb8cc2b5468c69edf45eb0ab579833ce7.tar.xz
linux-256856efb8cc2b5468c69edf45eb0ab579833ce7.zip
drm: rcar-du: Reject modes that fail CRTC timing requirements
The hardware requires the HDSR and VDSR registers to be set to 1 or higher. This translates to a minimum combined horizontal sync and back porch of 20 pixels and a minimum vertical back porch of 3 lines. Reject modes that fail those requirements. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Diffstat (limited to 'drivers/gpu/drm/rcar-du')
-rw-r--r--drivers/gpu/drm/rcar-du/rcar_du_crtc.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
index 79021d7aa3ce..90dacab67be5 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
@@ -735,10 +735,22 @@ enum drm_mode_status rcar_du_crtc_mode_valid(struct drm_crtc *crtc,
struct rcar_du_crtc *rcrtc = to_rcar_crtc(crtc);
struct rcar_du_device *rcdu = rcrtc->group->dev;
bool interlaced = mode->flags & DRM_MODE_FLAG_INTERLACE;
+ unsigned int vbp;
if (interlaced && !rcar_du_has(rcdu, RCAR_DU_FEATURE_INTERLACED))
return MODE_NO_INTERLACE;
+ /*
+ * The hardware requires a minimum combined horizontal sync and back
+ * porch of 20 pixels and a minimum vertical back porch of 3 lines.
+ */
+ if (mode->htotal - mode->hsync_start < 20)
+ return MODE_HBLANK_NARROW;
+
+ vbp = (mode->vtotal - mode->vsync_end) / (interlaced ? 2 : 1);
+ if (vbp < 3)
+ return MODE_VBLANK_NARROW;
+
return MODE_OK;
}