On Tue, Mar 24, 2009 at 03:04:59PM -0700, Luis R. Rodriguez wrote: > >> > Channel list is a good hint, maybe > >> > it's time to fix iw/nl80211 to send back all the channels :) > > > > I looked into yesterday actually, and it's completely non-trivial and > > requires userspace interface changes. > > Heh, there goes that idea then. Then in that case I'd advocate even > more trimming the channels down. Nick, what do you think of this? I think it's the best compromise for now - people can still get all the channels, normal users get a nice speedup in the default case. -------------------- >From 7289f60a3acf3bb1cfcc2a7ef7c4d88ffd0e13f1 Mon Sep 17 00:00:00 2001 From: Bob Copeland <me@xxxxxxxxxxxxxxx> Date: Sat, 28 Mar 2009 12:27:31 -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 that works with iw. This also halves scan time, from 10 seconds down to less than 5. Changes-licensed-under: 3-Clause-BSD Signed-off-by: Bob Copeland <me@xxxxxxxxxxxxxxx> --- drivers/net/wireless/ath5k/base.c | 21 +++++++++++++++++++++ 1 files changed, 21 insertions(+), 0 deletions(-) diff --git a/drivers/net/wireless/ath5k/base.c b/drivers/net/wireless/ath5k/base.c index 5d57d77..a018106 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 user 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) ? -- 1.6.0.6 -- Bob Copeland %% www.bobcopeland.com -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html