Measure the channel change time with the
bcm43xx tsf timer and remove the guesswork constant. ;)
Tests on my 4306 show that the time comes damn
close to reality.
Signed-off-by: Michael Buesch <[EMAIL PROTECTED]>
Index: wireless-dev/drivers/net/wireless/d80211/bcm43xx/bcm43xx_main.c
===================================================================
--- wireless-dev.orig/drivers/net/wireless/d80211/bcm43xx/bcm43xx_main.c
2006-05-03 18:12:27.000000000 +0200
+++ wireless-dev/drivers/net/wireless/d80211/bcm43xx/bcm43xx_main.c
2006-05-03 20:51:24.000000000 +0200
@@ -354,6 +354,33 @@
bcm43xx_write32(bcm, BCM43xx_MMIO_STATUS_BITFIELD, status);
}
+static void bcm43xx_measure_channel_change_time(struct bcm43xx_private *bcm)
+{
+ struct bcm43xx_radioinfo *radio;
+ u64 start, stop;
+ unsigned long flags;
+ u8 oldchan, testchan;
+
+ /* We (ab)use the bcm43xx TSF timer to measure the time needed
+ * to switch channels. This information is handed over to
+ * the ieee80211 subsystem.
+ * Time is measured in microseconds.
+ */
+
+ bcm43xx_lock_mmio(bcm, flags);
+ radio = bcm43xx_current_radio(bcm);
+ oldchan = radio->channel;
+ testchan = (oldchan == 6) ? 7 : 6;
+ bcm43xx_tsf_read(bcm, &start);
+ bcm43xx_radio_selectchannel(bcm, testchan, 0);
+ bcm43xx_tsf_read(bcm, &stop);
+ bcm43xx_radio_selectchannel(bcm, oldchan, 0);
+ bcm43xx_unlock_mmio(bcm, flags);
+
+ assert(stop > start);
+ bcm->ieee->channel_change_time = stop - start;
+}
+
static
void bcm43xx_macfilter_set(struct bcm43xx_private *bcm,
u16 offset,
@@ -3706,6 +3733,7 @@
dprintk(KERN_INFO PFX "80211 cores initialized\n");
bcm43xx_setup_modes(bcm);
bcm43xx_security_init(bcm);
+ bcm43xx_measure_channel_change_time(bcm);
ieee80211_update_hw(bcm->net_dev, bcm->ieee);
ieee80211_netif_oper(bcm->net_dev, NETIF_ATTACH);
ieee80211_netif_oper(bcm->net_dev, NETIF_START);
@@ -4329,7 +4357,6 @@
ieee->host_gen_beacon = 1;
ieee->rx_includes_fcs = 1;
ieee->monitor_during_oper = 1;
- ieee->channel_change_time = 20000;
ieee->tx = bcm43xx_net_hard_start_xmit;
ieee->open = bcm43xx_net_open;
ieee->stop = bcm43xx_net_stop;
--
Greetings Michael.
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