From: Edmund Dea <edmund.j.dea@xxxxxxxxx>
Monitors with vfp < 4 are not supported in KMB display. This change
prunes display modes with vfp < 4.
Fixes: 7f7b96a8a0a1 ("drm/kmb: Add support for KeemBay Display")
Signed-off-by: Edmund Dea <edmund.j.dea@xxxxxxxxx>
---
drivers/gpu/drm/kmb/kmb_crtc.c | 6 ++++++
drivers/gpu/drm/kmb/kmb_drv.h | 1 +
2 files changed, 7 insertions(+)
diff --git a/drivers/gpu/drm/kmb/kmb_crtc.c b/drivers/gpu/drm/kmb/kmb_crtc.c
index 42c8010ef2f6..0e42c40f0dce 100644
--- a/drivers/gpu/drm/kmb/kmb_crtc.c
+++ b/drivers/gpu/drm/kmb/kmb_crtc.c
@@ -191,6 +191,7 @@ static enum drm_mode_status
{
int refresh;
struct drm_device *dev = crtc->dev;
+ int vfp = mode->vsync_start - mode->vdisplay;
if (mode->vdisplay < KMB_CRTC_MAX_HEIGHT) {
drm_dbg(dev, "height = %d less than %d",
@@ -209,6 +210,11 @@ static enum drm_mode_status
return MODE_BAD;
}
+ if (vfp < KMB_CRTC_MIN_VFP) {
+ drm_dbg(dev, "vfp = %d less than %d", vfp, KMB_CRTC_MIN_VFP);
+ return MODE_BAD;
+ }
+
return MODE_OK;
}
diff --git a/drivers/gpu/drm/kmb/kmb_drv.h b/drivers/gpu/drm/kmb/kmb_drv.h
index dc0679a70cc5..c4af1d927e45 100644
--- a/drivers/gpu/drm/kmb/kmb_drv.h
+++ b/drivers/gpu/drm/kmb/kmb_drv.h
@@ -21,6 +21,7 @@
#define DRIVER_MINOR 2
/* Platform definitions */
+#define KMB_CRTC_MIN_VFP 4
#define KMB_CRTC_MAX_WIDTH 1920 /* max width in pixels */
#define KMB_CRTC_MAX_HEIGHT 1080 /* max height in pixels */
#define KMB_CRTC_MIN_WIDTH 1920
--
2.25.1
