From e38e12895022d7148220fc35782b5bd6461f1736 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
Date: Wed, 12 Jul 2017 18:52:54 +0300
Subject: [PATCH] drm/dp/mst: Use memchr_inv() instead of memcmp() against a
zeroed array
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We have memch_inv(), so no need to memcmp() against a zeroed temp array.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170712155254.26455-1-ville.syrjala@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
drivers/gpu/drm/drm_dp_mst_topology.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 552e71d5aa5fa..f7e292bf2baff 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -1337,15 +1337,17 @@ static void drm_dp_mst_link_probe_work(struct work_struct *work)
static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
u8 *guid)
{
- static u8 zero_guid[16];
+ u64 salt;
- if (!memcmp(guid, zero_guid, 16)) {
- u64 salt = get_jiffies_64();
- memcpy(&guid[0], &salt, sizeof(u64));
- memcpy(&guid[8], &salt, sizeof(u64));
- return false;
- }
- return true;
+ if (memchr_inv(guid, 0, 16))
+ return true;
+
+ salt = get_jiffies_64();
+
+ memcpy(&guid[0], &salt, sizeof(u64));
+ memcpy(&guid[8], &salt, sizeof(u64));
+
+ return false;
}
#if 0
--
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