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author | Vittorio Gambaletta <openwrt@vittgam.net> | 2017-03-14 14:45:15 +0100 |
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committer | Jo-Philipp Wich <jo@mein.io> | 2017-12-13 14:52:24 +0100 |
commit | 62a8252a0f32d6c148e4565354fd6a99da13fa41 (patch) | |
tree | a8babf16f54afb111fd9ca8fe920be470e171cc3 /package/kernel | |
parent | 5f03ce1213782c9ddb9bb010dac127bb554092cc (diff) | |
download | mtk-20170518-62a8252a0f32d6c148e4565354fd6a99da13fa41.zip mtk-20170518-62a8252a0f32d6c148e4565354fd6a99da13fa41.tar.gz mtk-20170518-62a8252a0f32d6c148e4565354fd6a99da13fa41.tar.bz2 |
mac80211: Fix race condition leading to wifi interfaces not coming up at boot sometimes.
In the drv_mac80211_setup function, mac80211_interface_cleanup
is called to ask the kernel to delete all existing interfaces
for the phy that is being configured via netlink.
Later in the first function, mac80211_prepare_vif is called to
set up the new interfaces as required.
But sometimes, when mac80211_prepare_vif (and so the relevant
`iw phy x interface add y` command) runs, the kernel might still
be cleaning up the old interface with the same ifname. It usually
takes very few time to do that; possibly a few milliseconds of
sleep in the script after detecting this error condition could be
enough, but the busybox sh does not support sub-second sleep
intervals.
When this happens, iw obviously fails to create the new interface;
and the following message is printed in the system log, followed by
subsequent failure messages from hostapd in case this would have been
an AP interface.
Tue Mar 14 04:21:57 2017 daemon.notice netifd: radio1 (2767): command failed: Too many open files in system (-23)
This was a long-standing issue existing since at least OpenWrt Backfire,
and today I finally managed to debug and (hopefully) solve it.
It was happening very few times on most devices; but it was happening
a lot more frequently on fast platforms with multiple radios, such as
the powerpc-based dual-ath9k-radio tl-wdr4900-v1.
Signed-off-by: Vittorio Gambaletta <openwrt@vittgam.net>
(cherry picked from commit 8301e613655c2d95fa5430a1a57d92d966fdc70b)
Diffstat (limited to 'package/kernel')
-rw-r--r-- | package/kernel/mac80211/files/lib/netifd/wireless/mac80211.sh | 32 |
1 files changed, 27 insertions, 5 deletions
diff --git a/package/kernel/mac80211/files/lib/netifd/wireless/mac80211.sh b/package/kernel/mac80211/files/lib/netifd/wireless/mac80211.sh index 82c3743..cda6f9f 100644 --- a/package/kernel/mac80211/files/lib/netifd/wireless/mac80211.sh +++ b/package/kernel/mac80211/files/lib/netifd/wireless/mac80211.sh @@ -411,6 +411,28 @@ mac80211_check_ap() { has_ap=1 } +mac80211_iw_interface_add() { + local phy="$1" + local ifname="$2" + local type="$3" + local wdsflag="$4" + local rc + + iw phy "$phy" interface add "$ifname" type "$type" $wdsflag + rc="$?" + + [ "$rc" = 233 ] && { + # Device might have just been deleted, give the kernel some time to finish cleaning it up + sleep 1 + + iw phy "$phy" interface add "$ifname" type "$type" $wdsflag + rc="$?" + } + + [ "$rc" != 0 ] && wireless_setup_failed INTERFACE_CREATION_FAILED + return $rc +} + mac80211_prepare_vif() { json_select config @@ -437,7 +459,7 @@ mac80211_prepare_vif() { # It is far easier to delete and create the desired interface case "$mode" in adhoc) - iw phy "$phy" interface add "$ifname" type adhoc + mac80211_iw_interface_add "$phy" "$ifname" adhoc || return ;; ap) # Hostapd will handle recreating the interface and @@ -451,21 +473,21 @@ mac80211_prepare_vif() { mac80211_hostapd_setup_bss "$phy" "$ifname" "$macaddr" "$type" || return [ -n "$hostapd_ctrl" ] || { - iw phy "$phy" interface add "$ifname" type __ap + mac80211_iw_interface_add "$phy" "$ifname" __ap || return hostapd_ctrl="${hostapd_ctrl:-/var/run/hostapd/$ifname}" } ;; mesh) - iw phy "$phy" interface add "$ifname" type mp + mac80211_iw_interface_add "$phy" "$ifname" mp || return ;; monitor) - iw phy "$phy" interface add "$ifname" type monitor + mac80211_iw_interface_add "$phy" "$ifname" monitor || return ;; sta) local wdsflag= staidx="$(($staidx + 1))" [ "$wds" -gt 0 ] && wdsflag="4addr on" - iw phy "$phy" interface add "$ifname" type managed $wdsflag + mac80211_iw_interface_add "$phy" "$ifname" managed "$wdsflag" || return [ "$powersave" -gt 0 ] && powersave="on" || powersave="off" iw "$ifname" set power_save "$powersave" ;; |