[PATCH 1/2] drm/fb_helper: make sure crtc_count is consistent

[Ilija Hadzic]

stop adding crtcs from dev->mode_config.crtc_list
to crtc_info array if gpu driver specifies (by mistake
or with a reason) fewer crtcs in crtc_count parameter

also, correct crtc_count value if gpu driver
specifies too many crtcs

Signed-off-by: Ilija Hadzic <ihadzic at research.bell-labs.com>
---
 drivers/gpu/drm/drm_fb_helper.c |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index f7c6854..feac888 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -466,10 +466,18 @@ int drm_fb_helper_init(struct drm_device *dev,
 
 	i = 0;
 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
+		if (i >= crtc_count) {
+			DRM_DEBUG("crtc count set by the gpu reached\n");
+			break;
+		}
 		fb_helper->crtc_info[i].crtc_id = crtc->base.id;
 		fb_helper->crtc_info[i].mode_set.crtc = crtc;
 		i++;
 	}
+	if (i < fb_helper->crtc_count) {
+		DRM_DEBUG("crtc count known by the drm reached\n");
+		fb_helper->crtc_count = i;
+	}
 	fb_helper->conn_limit = max_conn_count;
 	return 0;
 out_free:
-- 
1.7.7