From 42639fcd443d97a9a471f4b8269620286dd7036b Mon Sep 17 00:00:00 2001
From: Bob Copeland <me@bobcopeland.com>
Date: Mon, 30 Mar 2009 08:05:29 -0400
Subject: [PATCH] ath5k: reduce exported channel list
Claiming every available 5 ghz channel has a couple of negative
side-effects: scanning takes a long time, and the channel list
overflows the available buffer space for netlink commands,
resulting in:
$ iw phy phy0 info
command failed: No buffer space available (-105)
This patch adds a modparam so people who want to see all the channels
can do so by passing all_channels=1. By default users will see a
smaller list of channels. This also halves scan time, from 10 seconds
down to less than 5 when using world regulatory.
Changes-licensed-under: 3-Clause-BSD
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Reported-by: Simon Farnsworth <simon@farnz.org.uk>
Tested-By: Simon Farnsworth <simon@farnz.org.uk>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---
drivers/net/wireless/ath5k/base.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/drivers/net/wireless/ath5k/base.c b/drivers/net/wireless/ath5k/base.c
index a08bc8a4fb691..d8c60c53d953c 100644
--- a/drivers/net/wireless/ath5k/base.c
+++ b/drivers/net/wireless/ath5k/base.c
@@ -64,6 +64,10 @@ static int modparam_nohwcrypt;
module_param_named(nohwcrypt, modparam_nohwcrypt, int, 0444);
MODULE_PARM_DESC(nohwcrypt, "Disable hardware encryption.");
+static int modparam_all_channels;
+module_param_named(all_channels, modparam_all_channels, int, 0444);
+MODULE_PARM_DESC(all_channels, "Expose all channels the device can use.");
+
/******************\
* Internal defines *
@@ -862,6 +866,20 @@ ath5k_ieee2mhz(short chan)
return 2212 + chan * 20;
}
+/*
+ * Returns true for the channel numbers used without all_channels modparam.
+ */
+static bool ath5k_is_standard_channel(short chan)
+{
+ return ((chan <= 14) ||
+ /* UNII 1,2 */
+ ((chan & 3) == 0 && chan >= 36 && chan <= 64) ||
+ /* midband */
+ ((chan & 3) == 0 && chan >= 100 && chan <= 140) ||
+ /* UNII-3 */
+ ((chan & 3) == 1 && chan >= 149 && chan <= 165));
+}
+
static unsigned int
ath5k_copy_channels(struct ath5k_hw *ah,
struct ieee80211_channel *channels,
@@ -899,6 +917,9 @@ ath5k_copy_channels(struct ath5k_hw *ah,
if (!ath5k_channel_ok(ah, freq, chfreq))
continue;
+ if (!modparam_all_channels && !ath5k_is_standard_channel(ch))
+ continue;
+
/* Write channel info and increment counter */
channels[count].center_freq = freq;
channels[count].band = (chfreq == CHANNEL_2GHZ) ?
--
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