From bdef417d84536715145f6dc9cc3275c46f26295a Mon Sep 17 00:00:00 2001
From: Xiaomeng Tong <xiam0nd.tong@gmail.com>
Date: Sun, 27 Mar 2022 13:20:28 +0800
Subject: [PATCH] gma500: fix an incorrect NULL check on list iterator
Git-commit: bdef417d84536715145f6dc9cc3275c46f26295a
Patch-mainline: v5.19-rc1
References: git-fixes

The bug is here:
	return crtc;

The list iterator value 'crtc' will *always* be set and non-NULL by
list_for_each_entry(), so it is incorrect to assume that the iterator
value will be NULL if the list is empty or no element is found.

To fix the bug, return 'crtc' when found, otherwise return NULL.

Cc: stable@vger.kernel.org
Fixes: 89c78134cc54d ("gma500: Add Poulsbo support")
Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com>
Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220327052028.2013-1-xiam0nd.tong@gmail.com
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/gma500/psb_intel_display.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/gma500/psb_intel_display.c b/drivers/gpu/drm/gma500/psb_intel_display.c
index fb8234f4d128..dc467996cce4 100644
--- a/drivers/gpu/drm/gma500/psb_intel_display.c
+++ b/drivers/gpu/drm/gma500/psb_intel_display.c
@@ -524,14 +524,15 @@ void psb_intel_crtc_init(struct drm_device *dev, int pipe,
 
 struct drm_crtc *psb_intel_get_crtc_from_pipe(struct drm_device *dev, int pipe)
 {
-	struct drm_crtc *crtc = NULL;
+	struct drm_crtc *crtc;
 
 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
 		struct gma_crtc *gma_crtc = to_gma_crtc(crtc);
+
 		if (gma_crtc->pipe == pipe)
-			break;
+			return crtc;
 	}
-	return crtc;
+	return NULL;
 }
 
 int gma_connector_clones(struct drm_device *dev, int type_mask)
-- 
2.35.3