[openwrt/openwrt] mac80211: fix minstrel sample time check

[LEDE Commits]

nbd pushed a commit to openwrt/openwrt.git, branch openwrt-21.02:
https://git.openwrt.org/3839a4c7e98529362cffea70661a450fb072b360

commit 3839a4c7e98529362cffea70661a450fb072b360
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Thu Jun 17 12:40:15 2021 +0200

    mac80211: fix minstrel sample time check
    
    We need to skip sampling if the next sample time is after jiffies, not before.
    This patch fixes an issue where in some cases only very little sampling (or none
    at all) is performed, leading to really bad data rates
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
 ...ac80211-minstrel_ht-fix-sample-time-check.patch | 23 ++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/package/kernel/mac80211/patches/subsys/377-mac80211-minstrel_ht-fix-sample-time-check.patch b/package/kernel/mac80211/patches/subsys/377-mac80211-minstrel_ht-fix-sample-time-check.patch
new file mode 100644
index 0000000000..787254b4df
--- /dev/null
+++ b/package/kernel/mac80211/patches/subsys/377-mac80211-minstrel_ht-fix-sample-time-check.patch
@@ -0,0 +1,23 @@
+From: Felix Fietkau <nbd at nbd.name>
+Date: Thu, 17 Jun 2021 12:05:54 +0200
+Subject: [PATCH] mac80211: minstrel_ht: fix sample time check
+
+We need to skip sampling if the next sample time is after jiffies, not before.
+This patch fixes an issue where in some cases only very little sampling (or none
+at all) is performed, leading to really bad data rates
+
+Fixes: 80d55154b2f8 ("mac80211: minstrel_ht: significantly redesign the rate probing strategy")
+Signed-off-by: Felix Fietkau <nbd at nbd.name>
+---
+
+--- a/net/mac80211/rc80211_minstrel_ht.c
++++ b/net/mac80211/rc80211_minstrel_ht.c
+@@ -1498,7 +1498,7 @@ minstrel_ht_get_rate(void *priv, struct
+ 	    (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
+ 		return;
+ 
+-	if (time_is_before_jiffies(mi->sample_time))
++	if (time_is_after_jiffies(mi->sample_time))
+ 		return;
+ 
+ 	mi->sample_time = jiffies + MINSTREL_SAMPLE_INTERVAL;