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[3.13.y.z,extended,stable] Patch "iwlwifi: dvm: drop non VO frames when flushing" has been added to staging queue

Message ID 1415237334-27176-1-git-send-email-kamal@canonical.com
State New
Headers show

Commit Message

Kamal Mostafa Nov. 6, 2014, 1:28 a.m. UTC
This is a note to let you know that I have just added a patch titled

    iwlwifi: dvm: drop non VO frames when flushing

to the linux-3.13.y-queue branch of the 3.13.y.z 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 3.13.11.11.

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.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

From 7f339d7bed93fa50b6a3c807a304e91faf102beb Mon Sep 17 00:00:00 2001
From: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Date: Sun, 5 Oct 2014 09:11:14 +0300
Subject: iwlwifi: dvm: drop non VO frames when flushing

commit a0855054e59b0c5b2b00237fdb5147f7bcc18efb upstream.

When mac80211 wants to ensure that a frame is sent, it calls
the flush() callback. Until now, iwldvm implemented this by
waiting that all the frames are sent (ACKed or timeout).
In case of weak signal, this can take a significant amount
of time, delaying the next connection (in case of roaming).
Many users have reported that the flush would take too long
leading to the following error messages to be printed:

iwlwifi 0000:03:00.0: fail to flush all tx fifo queues Q 2
iwlwifi 0000:03:00.0: Current SW read_ptr 161 write_ptr 201
iwl data: 00000000: 00 00 00 00 00 00 00 00 fe ff 01 00 00 00 00 00
[snip]
iwlwifi 0000:03:00.0: FH TRBs(0) = 0x00000000
[snip]
iwlwifi 0000:03:00.0: Q 0 is active and mapped to fifo 3 ra_tid 0x0000 [9,9]
[snip]

Instead of waiting for these packets, simply drop them. This
significantly improves the responsiveness of the network.
Note that all the queues are flushed, but the VO one. This
is not typically used by the applications and it likely
contains management frames that are useful for connection
or roaming.

This bug is tracked here:
https://bugzilla.kernel.org/show_bug.cgi?id=56581

But it is duplicated in distributions' trackers.
A simple search in Ubuntu's database led to these bugs:

https://bugs.launchpad.net/ubuntu/+source/linux-firmware/+bug/1270808
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1305406
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1356236
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1360597
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1361809

Depends-on: 77be2c54c5bd ("mac80211: add vif to flush call")
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 drivers/net/wireless/iwlwifi/dvm/mac80211.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

--
1.9.1
diff mbox

Patch

diff --git a/drivers/net/wireless/iwlwifi/dvm/mac80211.c b/drivers/net/wireless/iwlwifi/dvm/mac80211.c
index bf1107a..7f0846e 100644
--- a/drivers/net/wireless/iwlwifi/dvm/mac80211.c
+++ b/drivers/net/wireless/iwlwifi/dvm/mac80211.c
@@ -1103,6 +1103,7 @@  static void iwlagn_mac_flush(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 			     u32 queues, bool drop)
 {
 	struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);
+	u32 scd_queues;

 	mutex_lock(&priv->mutex);
 	IWL_DEBUG_MAC80211(priv, "enter\n");
@@ -1116,18 +1117,19 @@  static void iwlagn_mac_flush(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 		goto done;
 	}

-	/*
-	 * mac80211 will not push any more frames for transmit
-	 * until the flush is completed
-	 */
-	if (drop) {
-		IWL_DEBUG_MAC80211(priv, "send flush command\n");
-		if (iwlagn_txfifo_flush(priv, 0)) {
-			IWL_ERR(priv, "flush request fail\n");
-			goto done;
-		}
+	scd_queues = BIT(priv->cfg->base_params->num_of_queues) - 1;
+	scd_queues &= ~(BIT(IWL_IPAN_CMD_QUEUE_NUM) |
+			BIT(IWL_DEFAULT_CMD_QUEUE_NUM));
+
+	if (vif)
+		scd_queues &= ~BIT(vif->hw_queue[IEEE80211_AC_VO]);
+
+	IWL_DEBUG_TX_QUEUES(priv, "Flushing SCD queues: 0x%x\n", scd_queues);
+	if (iwlagn_txfifo_flush(priv, scd_queues)) {
+		IWL_ERR(priv, "flush request fail\n");
+		goto done;
 	}
-	IWL_DEBUG_MAC80211(priv, "wait transmit/flush all frames\n");
+	IWL_DEBUG_TX_QUEUES(priv, "wait transmit/flush all frames\n");
 	iwl_trans_wait_tx_queue_empty(priv->trans);
 done:
 	mutex_unlock(&priv->mutex);