From: Jeykumar Sankaran <jsanka@codeaurora.org>
Date: Tue, 7 Aug 2018 19:56:51 -0700
Subject: drm/msm/disp/dpu: fix early dereference of physical encoder
Git-commit: 77a209cd7153cd758aa1b1417fb10017bead9454
Patch-mainline: v4.19-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

This change validates the physical encoder before it
is dereferenced.

Signed-off-by: Jeykumar Sankaran <jsanka@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -2444,6 +2444,8 @@ int dpu_encoder_wait_for_event(struct dr
 
 	for (i = 0; i < dpu_enc->num_phys_encs; i++) {
 		struct dpu_encoder_phys *phys = dpu_enc->phys_encs[i];
+		if (!phys)
+			continue;
 
 		switch (event) {
 		case MSM_ENC_COMMIT_DONE:
@@ -2461,7 +2463,7 @@ int dpu_encoder_wait_for_event(struct dr
 			return -EINVAL;
 		};
 
-		if (phys && fn_wait) {
+		if (fn_wait) {
 			DPU_ATRACE_BEGIN("wait_for_completion_event");
 			ret = fn_wait(phys);
 			DPU_ATRACE_END("wait_for_completion_event");