Tjyylli

Why didn't Tom Riddle take the presence of Fawkes and the Sorting Hat as more of a threat?

Is there a way to not have to poll the UART of an AVR?

Does an Eldritch Knight's Weapon Bond protect him from losing his weapon to a Telekinesis spell?

I have trouble understanding this fallacy: "If A, then B. Therefore if not-B, then not-A."

What to do with threats of blacklisting?

Renting a 2CV in France

In harmony: key or the flow?

Equivalent of "illegal" for violating civil law

What can I do to encourage my players to use their consumables?

Are the positive and negative planes inner or outer planes in the Great Wheel cosmology model?

Article. The word "Respect"

What is a good reason for every spaceship to carry a weapon on board?

What makes papers publishable in top-tier journals?

Should I cite R or RStudio?

What's this assembly doing?

How do I prevent a homebrew Grappling Hook feature from trivializing Tomb of Annihilation?

How to politely refuse in-office gym instructor for steroids and protein

Custom shape shows unwanted extra line

Can we "borrow" our answers to populate our own websites?

What species should be used for storage of human minds?

Is there a way to store 9th-level spells in a Glyph of Warding or similar method?

Midterm in Mathematics Courses

Is there a file that always exists and a 'normal' user can't lstat it?

How to write cases in LaTeX?

How can I prevent the kernel from limiting TX power as advertised by AP

Problem with wireless networkingLinux I2C Communication from Kernel Spaceubuntu (linuxmint) not reconnecting to wireless after router rebootWhere can I find the Linux kernel file?Kernel hacking methodology - how to find out where to hack the linux kernelwhich module of linux kernel can be loaded dynamicUDP packets from kernelHow to get config from a EFISTUB kernel?How can I safely delete the old kernel version from the /boot partition on Ubuntu?Replacing linux kernel from outside of system

5

4

I am connecting to eduroam over a distance of about 150m using an external 23dBm Antenna and an Ubiquiti SR71-E with an Atheros AR9285 chip. My system is Debian Jessie server - so the connection is managed by wpa_supplicant. Authentication timeouts caused stability issues with the connection. Migrating to the backports Kernel 4.7.0 solved these.

But now the kernel is reducing tx-power as advertised by the (Cisco) AP. This function can be found under "has_80211h_pwr" and "has_cisco_pwr" in

http://lxr.free-electrons.com/source/net/mac80211/mlme.c

The problem is that

iwconfig wlan0 txpower XX
iw dev wlan0 set txpower fixed XXXX

only allow setting the txpower between 0 and the new limit. As the AP advertises a limit of 8dbm the connection is forced to go to 1 Mb/s and still has high counts on "Tx excessive retries" and "Invalid misc".

linux wireless-networking linux-kernel debian-jessie

share|improve this question

edited Nov 7 '16 at 12:31

Felix

asked Nov 7 '16 at 11:27

FelixFelix

265

add a comment | 

5

4

I am connecting to eduroam over a distance of about 150m using an external 23dBm Antenna and an Ubiquiti SR71-E with an Atheros AR9285 chip. My system is Debian Jessie server - so the connection is managed by wpa_supplicant. Authentication timeouts caused stability issues with the connection. Migrating to the backports Kernel 4.7.0 solved these.

But now the kernel is reducing tx-power as advertised by the (Cisco) AP. This function can be found under "has_80211h_pwr" and "has_cisco_pwr" in

http://lxr.free-electrons.com/source/net/mac80211/mlme.c

The problem is that

iwconfig wlan0 txpower XX
iw dev wlan0 set txpower fixed XXXX

only allow setting the txpower between 0 and the new limit. As the AP advertises a limit of 8dbm the connection is forced to go to 1 Mb/s and still has high counts on "Tx excessive retries" and "Invalid misc".

linux wireless-networking linux-kernel debian-jessie

share|improve this question

edited Nov 7 '16 at 12:31

Felix

asked Nov 7 '16 at 11:27

FelixFelix

265

add a comment | 

I am connecting to eduroam over a distance of about 150m using an external 23dBm Antenna and an Ubiquiti SR71-E with an Atheros AR9285 chip. My system is Debian Jessie server - so the connection is managed by wpa_supplicant. Authentication timeouts caused stability issues with the connection. Migrating to the backports Kernel 4.7.0 solved these.

But now the kernel is reducing tx-power as advertised by the (Cisco) AP. This function can be found under "has_80211h_pwr" and "has_cisco_pwr" in

http://lxr.free-electrons.com/source/net/mac80211/mlme.c

The problem is that

iwconfig wlan0 txpower XX
iw dev wlan0 set txpower fixed XXXX

only allow setting the txpower between 0 and the new limit. As the AP advertises a limit of 8dbm the connection is forced to go to 1 Mb/s and still has high counts on "Tx excessive retries" and "Invalid misc".

linux wireless-networking linux-kernel debian-jessie

share|improve this question

edited Nov 7 '16 at 12:31

Felix

asked Nov 7 '16 at 11:27

FelixFelix

265

share|improve this question

edited Nov 7 '16 at 12:31

Felix

asked Nov 7 '16 at 11:27

FelixFelix

265

share|improve this question

edited Nov 7 '16 at 12:31

Felix

asked Nov 7 '16 at 11:27

FelixFelix

265

asked Nov 7 '16 at 11:27

FelixFelix

265

asked Nov 7 '16 at 11:27

FelixFelix

265

1 Answer
1

active

oldest

votes

0

Here's a patch that should ignore annoying 802.11h frames from AP's when setting txpower to "fixed".

diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c

index d6a1a46..f3ee9ab 100644

--- a/net/mac80211/iface.c

+++ b/net/mac80211/iface.c

@@ -61,7 +61,8 @@  bool __ieee80211_recalc_txpower(struct ieee80211_sub_if_data *sdata)

    if (sdata->user_power_level != IEEE80211_UNSET_POWER_LEVEL)

        power = min(power, sdata->user_power_level);



-   if (sdata->ap_power_level != IEEE80211_UNSET_POWER_LEVEL)

+   if (sdata->ap_power_level != IEEE80211_UNSET_POWER_LEVEL &&

+       sdata->vif.bss_conf.txpower_type != NL80211_TX_POWER_FIXED)

        power = min(power, sdata->ap_power_level);



    if (power != sdata->vif.bss_conf.txpower) {

share|improve this answer

answered 6 hours ago

Andreas Søvik NilsenAndreas Søvik Nilsen

1

New contributor

Andreas Søvik Nilsen is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

add a comment | 

Your Answer

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "3"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Sign up using Google

Sign up using Facebook

Sign up using Email and Password

Post as a guest

Name

Email

Required, but never shown

StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fsuperuser.com%2fquestions%2f1143229%2fhow-can-i-prevent-the-kernel-from-limiting-tx-power-as-advertised-by-ap%23new-answer', 'question_page');
}
);

Post as a guest

Name

Email

Required, but never shown

0

Here's a patch that should ignore annoying 802.11h frames from AP's when setting txpower to "fixed".

diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c

index d6a1a46..f3ee9ab 100644

--- a/net/mac80211/iface.c

+++ b/net/mac80211/iface.c

@@ -61,7 +61,8 @@  bool __ieee80211_recalc_txpower(struct ieee80211_sub_if_data *sdata)

    if (sdata->user_power_level != IEEE80211_UNSET_POWER_LEVEL)

        power = min(power, sdata->user_power_level);



-   if (sdata->ap_power_level != IEEE80211_UNSET_POWER_LEVEL)

+   if (sdata->ap_power_level != IEEE80211_UNSET_POWER_LEVEL &&

+       sdata->vif.bss_conf.txpower_type != NL80211_TX_POWER_FIXED)

        power = min(power, sdata->ap_power_level);



    if (power != sdata->vif.bss_conf.txpower) {

share|improve this answer

answered 6 hours ago

Andreas Søvik NilsenAndreas Søvik Nilsen

1

New contributor

Andreas Søvik Nilsen is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

add a comment | 

0

Here's a patch that should ignore annoying 802.11h frames from AP's when setting txpower to "fixed".

diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c

index d6a1a46..f3ee9ab 100644

--- a/net/mac80211/iface.c

+++ b/net/mac80211/iface.c

@@ -61,7 +61,8 @@  bool __ieee80211_recalc_txpower(struct ieee80211_sub_if_data *sdata)

    if (sdata->user_power_level != IEEE80211_UNSET_POWER_LEVEL)

        power = min(power, sdata->user_power_level);



-   if (sdata->ap_power_level != IEEE80211_UNSET_POWER_LEVEL)

+   if (sdata->ap_power_level != IEEE80211_UNSET_POWER_LEVEL &&

+       sdata->vif.bss_conf.txpower_type != NL80211_TX_POWER_FIXED)

        power = min(power, sdata->ap_power_level);



    if (power != sdata->vif.bss_conf.txpower) {

share|improve this answer

answered 6 hours ago

Andreas Søvik NilsenAndreas Søvik Nilsen

1

New contributor

Andreas Søvik Nilsen is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

add a comment | 

Here's a patch that should ignore annoying 802.11h frames from AP's when setting txpower to "fixed".

diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c

index d6a1a46..f3ee9ab 100644

--- a/net/mac80211/iface.c

+++ b/net/mac80211/iface.c

@@ -61,7 +61,8 @@  bool __ieee80211_recalc_txpower(struct ieee80211_sub_if_data *sdata)

    if (sdata->user_power_level != IEEE80211_UNSET_POWER_LEVEL)

        power = min(power, sdata->user_power_level);



-   if (sdata->ap_power_level != IEEE80211_UNSET_POWER_LEVEL)

+   if (sdata->ap_power_level != IEEE80211_UNSET_POWER_LEVEL &&

+       sdata->vif.bss_conf.txpower_type != NL80211_TX_POWER_FIXED)

        power = min(power, sdata->ap_power_level);



    if (power != sdata->vif.bss_conf.txpower) {

share|improve this answer

answered 6 hours ago

Andreas Søvik NilsenAndreas Søvik Nilsen

1

New contributor

Andreas Søvik Nilsen is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c

index d6a1a46..f3ee9ab 100644

--- a/net/mac80211/iface.c

+++ b/net/mac80211/iface.c

@@ -61,7 +61,8 @@  bool __ieee80211_recalc_txpower(struct ieee80211_sub_if_data *sdata)

    if (sdata->user_power_level != IEEE80211_UNSET_POWER_LEVEL)

        power = min(power, sdata->user_power_level);



-   if (sdata->ap_power_level != IEEE80211_UNSET_POWER_LEVEL)

+   if (sdata->ap_power_level != IEEE80211_UNSET_POWER_LEVEL &&

+       sdata->vif.bss_conf.txpower_type != NL80211_TX_POWER_FIXED)

        power = min(power, sdata->ap_power_level);



    if (power != sdata->vif.bss_conf.txpower) {

share|improve this answer

answered 6 hours ago

Andreas Søvik NilsenAndreas Søvik Nilsen

1

New contributor

Andreas Søvik Nilsen is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

answered 6 hours ago

Andreas Søvik NilsenAndreas Søvik Nilsen

1

New contributor

Andreas Søvik Nilsen is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

answered 6 hours ago

Andreas Søvik NilsenAndreas Søvik Nilsen

1