From e38e12895022d7148220fc35782b5bd6461f1736 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Wed, 12 Jul 2017 18:52:54 +0300 Subject: [PATCH] drm/dp/mst: Use memchr_inv() instead of memcmp() against a zeroed array MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit We have memch_inv(), so no need to memcmp() against a zeroed temp array. Signed-off-by: Ville Syrjälä Link: http://patchwork.freedesktop.org/patch/msgid/20170712155254.26455-1-ville.syrjala@linux.intel.com Reviewed-by: Daniel Vetter --- 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 552e71d5aa5f..f7e292bf2baf 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 -- 2.20.1