| Message ID | 1428357471-14316-1-git-send-email-kamal@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 101bccf..09cb1052 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -561,6 +561,7 @@ ieee80211_tx_h_check_control_port_protocol(struct ieee80211_tx_data *tx) if (tx->sdata->control_port_no_encrypt) info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; info->control.flags |= IEEE80211_TX_CTRL_PORT_CTRL_PROTO; + info->flags |= IEEE80211_TX_CTL_USE_MINRATE; } return TX_CONTINUE;
This is a note to let you know that I have just added a patch titled mac80211: Send EAPOL frames at lowest rate to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue This patch is scheduled to be released in version 3.13.11-ckt19. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.13.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From 184af4369c644dddbb29722b6ea24c7102cc0200 Mon Sep 17 00:00:00 2001 From: Jouni Malinen <jouni@qca.qualcomm.com> Date: Thu, 26 Feb 2015 15:50:50 +0200 Subject: mac80211: Send EAPOL frames at lowest rate commit 9c1c98a3bb7b7593b60264b9a07e001e68b46697 upstream. The current minstrel_ht rate control behavior is somewhat optimistic in trying to find optimum TX rate. While this is usually fine for normal Data frames, there are cases where a more conservative set of retry parameters would be beneficial to make the connection more robust. EAPOL frames are critical to the authentication and especially the EAPOL-Key message 4/4 (the last message in the 4-way handshake) is important to get through to the AP. If that message is lost, the only recovery mechanism in many cases is to reassociate with the AP and start from scratch. This can often be avoided by trying to send the frame with more conservative rate and/or with more link layer retries. In most cases, minstrel_ht is currently using the initial EAPOL-Key frames for probing higher rates and this results in only five link layer transmission attempts (one at high(ish) MCS and four at MCS0). While this works with most APs, it looks like there are some deployed APs that may have issues with the EAPOL frames using HT MCS immediately after association. Similarly, there may be issues in cases where the signal strength or radio environment is not good enough to be able to get frames through even at couple of MCS 0 tries. The best approach for this would likely to be to reduce the TX rate for the last rate (3rd rate parameter in the set) to a low basic rate (say, 6 Mbps on 5 GHz and 2 or 5.5 Mbps on 2.4 GHz), but doing that cleanly requires some more effort. For now, we can start with a simple one-liner that forces the minimum rate to be used for EAPOL frames similarly how the TX rate is selected for the IEEE 802.11 Management frames. This does result in a small extra latency added to the cases where the AP would be able to receive the higher rate, but taken into account how small number of EAPOL frames are used, this is likely to be insignificant. A future optimization in the minstrel_ht design can also allow this patch to be reverted to get back to the more optimized initial TX rate. It should also be noted that many drivers that do not use minstrel as the rate control algorithm are already doing similar workarounds by forcing the lowest TX rate to be used for EAPOL frames. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Tested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- net/mac80211/tx.c | 1 + 1 file changed, 1 insertion(+) -- 1.9.1