[PATCH] drm: fixes crct set_mode when encoder mode_fixup is null.

[Carlos Palminha]

Avoids null crash when encoders don't implement mode_fixup.

Signed-off-by: Carlos Palminha <palminha at synopsys.com>
---
 drivers/gpu/drm/drm_crtc_helper.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
index a02a7f9..ef3def7 100644
--- a/drivers/gpu/drm/drm_crtc_helper.c
+++ b/drivers/gpu/drm/drm_crtc_helper.c
@@ -328,10 +328,12 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
 		}
 
 		encoder_funcs = encoder->helper_private;
-		if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
-						      adjusted_mode))) {
-			DRM_DEBUG_KMS("Encoder fixup failed\n");
-			goto done;
+		if (encoder_funcs->mode_fixup) {
+			if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
+							      adjusted_mode))) {
+				DRM_DEBUG_KMS("Encoder fixup failed\n");
+				goto done;
+			}
 		}
 	}
 
-- 
2.5.0