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mac80211: fix 2.4 GHz 40 MHz disabling

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The module parameter ieee80211_disable_40mhz_24ghz
was meant to allow disabling 40 MHz operation in
the 2.4 GHz band by default. However, it is buggy
as implemented because while it advertises to the
AP that the device doesn't support 40 MHz, it will
itself still use 40 MHz configurations.

To fix this, clear the 40 MHz bits from the sband
completely instead of overriding where used.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Johannes Berg
2011-02-16 08:46:58 +01:00
committed by John W. Linville
parent 9bf8ab35f2
commit 8ba0537c62
4 changed files with 13 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
net/mac80211/main.c
View File

@ -34,7 +34,7 @@
#include "debugfs.h"
bool ieee80211_disable_40mhz_24ghz;
static bool ieee80211_disable_40mhz_24ghz;
module_param(ieee80211_disable_40mhz_24ghz, bool, 0644);
MODULE_PARM_DESC(ieee80211_disable_40mhz_24ghz,
"Disable 40MHz support in the 2.4GHz band");
@ -723,6 +723,18 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
}
channels += sband->n_channels;
/*
* Since ieee80211_disable_40mhz_24ghz is global, we can
* modify the sband's ht data even if the driver uses a
* global structure for that.
*/
if (ieee80211_disable_40mhz_24ghz &&
band == IEEE80211_BAND_2GHZ &&
sband->ht_cap.ht_supported) {
sband->ht_cap.cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
sband->ht_cap.cap &= ~IEEE80211_HT_CAP_SGI_40;
}
if (max_bitrates < sband->n_bitrates)
max_bitrates = sband->n_bitrates;
supp_ht = supp_ht || sband->ht_cap.ht_supported;