[3.16.y-ckt stable] Patch "iwlwifi: make U-APSD default configurable at compile time" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    iwlwifi: make U-APSD default configurable at compile time

to the linux-3.16.y-queue branch of the 3.16.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-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt4.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 2bedb4a1e90c3fe708089554e614c2a2c46062cb Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg at intel.com>
Date: Mon, 1 Sep 2014 11:28:11 +0200
Subject: iwlwifi: make U-APSD default configurable at compile time

commit d6ca18de129fc4dd4374389561930b32820f35ff upstream.

With a significant number of deployed APs, enabling uAPSD leads to the
AP never using aggregation sessions (likely due to the complexities
involved in handling uAPSD in those.) This obviously results in a large
drop in throughput with such APs.

On the other hand, uAPSD can result in some power consumption benefits,
but for now just disable it to get performance with affected APs back
up.

Signed-off-by: Johannes Berg <johannes.berg at intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach at intel.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/net/wireless/iwlwifi/Kconfig   | 10 ++++++++++
 drivers/net/wireless/iwlwifi/iwl-drv.c |  8 +++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/iwlwifi/Kconfig b/drivers/net/wireless/iwlwifi/Kconfig
index 7fd50428b934..9c67e255c689 100644
--- a/drivers/net/wireless/iwlwifi/Kconfig
+++ b/drivers/net/wireless/iwlwifi/Kconfig
@@ -85,6 +85,16 @@ config IWLWIFI_BCAST_FILTERING
 	  If unsure, don't enable this option, as some programs might
 	  expect incoming broadcasts for their normal operations.

+config IWLWIFI_UAPSD
+	bool "enable U-APSD by default"
+	depends on IWLMVM
+	help
+	  Say Y here to enable U-APSD by default. This may cause
+	  interoperability problems with some APs, manifesting in lower than
+	  expected throughput due to those APs not enabling aggregation
+
+	  If unsure, say N.
+
 menu "Debugging Options"
 	depends on IWLWIFI

diff --git a/drivers/net/wireless/iwlwifi/iwl-drv.c b/drivers/net/wireless/iwlwifi/iwl-drv.c
index f2a5c12269a3..a09ce04c0f63 100644
--- a/drivers/net/wireless/iwlwifi/iwl-drv.c
+++ b/drivers/net/wireless/iwlwifi/iwl-drv.c
@@ -1243,7 +1243,9 @@ struct iwl_mod_params iwlwifi_mod_params = {
 	.bt_coex_active = true,
 	.power_level = IWL_POWER_INDEX_1,
 	.wd_disable = true,
-	.uapsd_disable = false,
+#ifndef CONFIG_IWLWIFI_UAPSD
+	.uapsd_disable = true,
+#endif /* CONFIG_IWLWIFI_UAPSD */
 	/* the rest are 0 by default */
 };
 IWL_EXPORT_SYMBOL(iwlwifi_mod_params);
@@ -1359,7 +1361,11 @@ MODULE_PARM_DESC(nvm_file, "NVM file name");

 module_param_named(uapsd_disable, iwlwifi_mod_params.uapsd_disable,
 		   bool, S_IRUGO);
+#ifdef CONFIG_IWLWIFI_UAPSD
 MODULE_PARM_DESC(uapsd_disable, "disable U-APSD functionality (default: N)");
+#else
+MODULE_PARM_DESC(uapsd_disable, "disable U-APSD functionality (default: Y)");
+#endif

 /*
  * set bt_coex_active to true, uCode will do kill/defer
--
2.1.4