From: Inki Dae <inki.dae@samsung.com>
Date: Tue, 11 Aug 2015 12:23:49 +0000 (+0900)
Subject: drm/atomic: fix null pointer access to mode_fixup callback
X-Git-Tag: v4.3-rc1~75^2~32^2~15
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=845249172a363c2217af5926fac17f58c7228aa4;p=linux.git

drm/atomic: fix null pointer access to mode_fixup callback

This patch fixes null pointer access incurred when
encoder driver didn't set its own mode_fixup callback.

mode_fixup callback shoudn't be called if the callback
of drm_encoder_helper_funcs is NULL.

Changelog v2:
- change it to else if

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 0b475fae067d..96e08e940ed0 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -299,7 +299,7 @@ mode_fixup(struct drm_atomic_state *state)
 						 encoder->base.id, encoder->name);
 				return ret;
 			}
-		} else {
+		} else if (funcs->mode_fixup) {
 			ret = funcs->mode_fixup(encoder, &crtc_state->mode,
 						&crtc_state->adjusted_mode);
 			if (!ret) {