[ath9k-devel] weak signal strength using ar928x

[ath9k-devel] weak signal strength using ar928x

[Porsch, Marco]

Hello list,

i'm experiencing a very weak signal strength using ath9k and ar928x wireless in a wndr3700 router. I placed two of these approximately 3 meters line of sight of each other, and see signal strength of about -90dbm in mesh mode [1].
The problem counts for sending and receiving, also in bss-mode. I posed my laptop approximately one meter away from the router as ap and measured the signal strength of the netgear firmware (openwrt 7.x with propietary driver) and openwrt (compat-wireless-2010-01-11, compat-wireless-2009-12-05), which gives me 20dbm difference [2].
Using 'iwlist scan', original firmware shows 14 APs in my neighbourhood, openwrt shows 4.

[3] relevant boot output

[4] lspci

Regards
Marco



[1]
Station 00:24:b2:59:00:62 (on imesh2g)
	inactive time:	652430 ms
	rx bytes:	1070
	rx packets:	15
	tx bytes:	2164
	tx packets:	32
	signal:  	-90 dBm
	tx bitrate:	1.0 MBit/s
	mesh llid:	32214
	mesh plid:	5622
	mesh plink:	ESTAB


[2]
 Cell 28 - Address: 00:24:B2:58:FB:52
                    ESSID:"NETGEAR"
                    Protocol:IEEE 802.11bg
                    Mode:Master
                    Frequency:2.417 GHz (Channel 2)
                    Encryption key:off
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
                              9 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s
                              48 Mb/s; 54 Mb/s
                    Quality=73/100  Signal level=-55 dBm  
                    Extra: Last beacon: 12ms ago

 Cell 24 - Address: 00:24:B2:58:FB:52
                    ESSID:"openWrt"
                    Protocol:IEEE 802.11bg
                    Mode:Master
                    Frequency:2.417 GHz (Channel 2)
                    Encryption key:off
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
                              9 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s
                              48 Mb/s; 54 Mb/s
                    Quality=46/100  Signal level=-73 dBm  
                    Extra: Last beacon: 168ms ago


[3]
PCI: Enabling device 0000:00:11.0 (0000 -> 0002)
ath: EEPROM regdomain: 0x60
ath: EEPROM indicates we should expect a direct regpair map
ath: Country alpha2 being used: 00
ath: Regpair used: 0x60
phy0: Selected rate control algorithm 'ath9k_rate_control'
Registered led device: ath9k-phy0::radio
Registered led device: ath9k-phy0::assoc
Registered led device: ath9k-phy0::tx
Registered led device: ath9k-phy0::rx
phy0: Atheros AR9280 Rev:2 mem=0xb0000000, irq=48
PCI: Enabling device 0000:00:12.0 (0000 -> 0002)
ath: EEPROM regdomain: 0x60
ath: EEPROM indicates we should expect a direct regpair map
ath: Country alpha2 being used: 00
ath: Regpair used: 0x60
phy1: Selected rate control algorithm 'ath9k_rate_control'
Registered led device: ath9k-phy1::radio
Registered led device: ath9k-phy1::assoc
Registered led device: ath9k-phy1::tx
Registered led device: ath9k-phy1::rx
phy1: Atheros AR9280 Rev:2 mem=0xb0010000, irq=49


[4]
root at WNDR3700:/# cat proc/pci 
PCI devices found:
  Bus  0, device   0, function  0:
    Class 0280: PCI device 168c:0029 (rev 1).
      IRQ 48.
      Master Capable.  Latency=168.  
      Non-prefetchable 32 bit memory at 0x10000000 [0x1000ffff].
  Bus  0, device   1, function  0:
    Class 0280: PCI device 168c:0029 (rev 1).
      IRQ 49.
      Master Capable.  Latency=168.  
      Non-prefetchable 32 bit memory at 0x10010000 [0x1001ffff].

[ath9k-devel] weak signal strength using ar928x

[Porsch, Marco]

> Hello list,

> i'm experiencing a very weak signal strength using ath9k and ar928x wireless in a wndr3700 router. I placed two of these approximately 3 meters line of sight of each other, and see signal strength of about -90dbm in mesh mode [1].
> The problem counts for sending and receiving, also in bss-mode. I posed my laptop approximately one meter away from the router as ap and measured the signal strength of the netgear firmware (openwrt 7.x with propietary driver) and openwrt (compat-wireless-2010-01-11, compat-wireless-2009-12-05), which gives me 20dbm difference [2].
> Using 'iwlist scan', original firmware shows 14 APs in my neighbourhood, openwrt shows 4.

[...]

I have taken a further look into the problem and realized, that 'iwconfig txpower' has no affect to the signal strength. I also tried up-down or scanning after change.
A test with hacked 'regd.c' (all set to 30dBm, no further limitations) also showed no changes in signal quality. Power management is off.

A interesting detail is, that 5GHz (channel 52) also has quiet limited range, but far better than 2,4GHz. 5GHz txpower is set to 30dBm by default.

Kernel is Linux OpenWrt 2.6.30.10 #10 Fri Jan 15 11:12:04 CET 2010 mips, wireless now from compat-wireless-2010-01-13.


Some debug outputs after 10min of iperf traffic over mesh-link between two identical wndr3700. I have seen no other 5GHz wifi in range.
1) 3 meters line of sight
2) 10 meters with thin glass/metal walls
   (in both cases 2,4GHz wont communicate at all)


1)
[  3]  0.0-600.0 sec  1.27 GBytes  18.2 Mbits/sec

cat /sys/kernel/debug/ath9k/phy1/rcstat
    HT    MCS   Rate    Success    Retries   XRetries        PER
                6.0:          0          0          0          0
                9.0:          0          0          0          0
               12.0:          0          0          0          0
               18.0:          0          0          0          0
               24.0:          1          0          0          0
               36.0:          1          0          0          0
               48.0:        286         19          0          0
               54.0:    1160839     113918         26          7

Station 00:24:b2:58:fb:54 (on imesh5g)
        inactive time:  570 ms
        rx bytes:       2907897221
        rx packets:     2001025
        tx bytes:       422706850
        tx packets:     1161637
        signal:         -67 dBm
        tx bitrate:     54.0 MBit/s
        mesh llid:      4935
        mesh plid:      19635
        mesh plink:     ESTAB


2)
[  3]  0.0-600.0 sec    294 MBytes  4.11 Mbits/sec

cat /sys/kernel/debug/ath9k/phy1/rcstat 
    HT    MCS   Rate    Success    Retries   XRetries        PER
                6.0:       6936       7587       2100          0
                9.0:      17804      18453       5797          0
               12.0:     153370     112773      21194         13
               18.0:      40331     104799      45526         49
               24.0:         94       4822       7450         54
               36.0:          0         15         21         82
               48.0:          0          0          0          0
               54.0:          0          0          0          0

Station 00:24:b2:58:fb:54 (on imesh5g)
        inactive time:  800 ms
        rx bytes:       670383000
        rx packets:     442114
        tx bytes:       18396981
        tx packets:     218811
        signal:         -86 dBm
        tx bitrate:     12.0 MBit/s
        mesh llid:      57085
        mesh plid:      19775
        mesh plink:     ESTAB

[ath9k-devel] weak signal strength using ar928x

[Lorenzo Bianconi]

>> Hello list,
>
>> i'm experiencing a very weak signal strength using ath9k and ar928x wireless in a wndr3700 router. I placed two of these approximately 3 meters line of sight of each other, and see signal strength of about -90dbm in mesh mode [1].
>> The problem counts for sending and receiving, also in bss-mode. I posed my laptop approximately one meter away from the router as ap and measured the signal strength of the netgear firmware (openwrt 7.x with propietary driver) and openwrt (compat-wireless-2010-01-11, compat-wireless-2009-12-05), which gives me 20dbm difference [2].
>> Using 'iwlist scan', original firmware shows 14 APs in my neighbourhood, openwrt shows 4.
>
> [...]
>
> I have taken a further look into the problem and realized, that 'iwconfig txpower' has no affect to the signal strength. I also tried up-down or scanning after change.
> A test with hacked 'regd.c' (all set to 30dBm, no further limitations) also showed no changes in signal quality. Power management is off.
>
> A interesting detail is, that 5GHz (channel 52) also has quiet limited range, but far better than 2,4GHz. 5GHz txpower is set to 30dBm by default.
>
> Kernel is Linux OpenWrt 2.6.30.10 #10 Fri Jan 15 11:12:04 CET 2010 mips, wireless now from compat-wireless-2010-01-13.
>
>
> Some debug outputs after 10min of iperf traffic over mesh-link between two identical wndr3700. I have seen no other 5GHz wifi in range.
> 1) 3 meters line of sight
> 2) 10 meters with thin glass/metal walls
> ? (in both cases 2,4GHz wont communicate at all)
>
>
> 1)
> [ ?3] ?0.0-600.0 sec ?1.27 GBytes ?18.2 Mbits/sec
>
> cat /sys/kernel/debug/ath9k/phy1/rcstat
> ? ?HT ? ?MCS ? Rate ? ?Success ? ?Retries ? XRetries ? ? ? ?PER
> ? ? ? ? ? ? ? ?6.0: ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
> ? ? ? ? ? ? ? ?9.0: ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
> ? ? ? ? ? ? ? 12.0: ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
> ? ? ? ? ? ? ? 18.0: ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
> ? ? ? ? ? ? ? 24.0: ? ? ? ? ?1 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
> ? ? ? ? ? ? ? 36.0: ? ? ? ? ?1 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
> ? ? ? ? ? ? ? 48.0: ? ? ? ?286 ? ? ? ? 19 ? ? ? ? ?0 ? ? ? ? ?0
> ? ? ? ? ? ? ? 54.0: ? ?1160839 ? ? 113918 ? ? ? ? 26 ? ? ? ? ?7
>
> Station 00:24:b2:58:fb:54 (on imesh5g)
> ? ? ? ?inactive time: ?570 ms
> ? ? ? ?rx bytes: ? ? ? 2907897221
> ? ? ? ?rx packets: ? ? 2001025
> ? ? ? ?tx bytes: ? ? ? 422706850
> ? ? ? ?tx packets: ? ? 1161637
> ? ? ? ?signal: ? ? ? ? -67 dBm
> ? ? ? ?tx bitrate: ? ? 54.0 MBit/s
> ? ? ? ?mesh llid: ? ? ?4935
> ? ? ? ?mesh plid: ? ? ?19635
> ? ? ? ?mesh plink: ? ? ESTAB
>
>
> 2)
> [ ?3] ?0.0-600.0 sec ? ?294 MBytes ?4.11 Mbits/sec
>
> cat /sys/kernel/debug/ath9k/phy1/rcstat
> ? ?HT ? ?MCS ? Rate ? ?Success ? ?Retries ? XRetries ? ? ? ?PER
> ? ? ? ? ? ? ? ?6.0: ? ? ? 6936 ? ? ? 7587 ? ? ? 2100 ? ? ? ? ?0
> ? ? ? ? ? ? ? ?9.0: ? ? ?17804 ? ? ?18453 ? ? ? 5797 ? ? ? ? ?0
> ? ? ? ? ? ? ? 12.0: ? ? 153370 ? ? 112773 ? ? ?21194 ? ? ? ? 13
> ? ? ? ? ? ? ? 18.0: ? ? ?40331 ? ? 104799 ? ? ?45526 ? ? ? ? 49
> ? ? ? ? ? ? ? 24.0: ? ? ? ? 94 ? ? ? 4822 ? ? ? 7450 ? ? ? ? 54
> ? ? ? ? ? ? ? 36.0: ? ? ? ? ?0 ? ? ? ? 15 ? ? ? ? 21 ? ? ? ? 82
> ? ? ? ? ? ? ? 48.0: ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
> ? ? ? ? ? ? ? 54.0: ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
>
> Station 00:24:b2:58:fb:54 (on imesh5g)
> ? ? ? ?inactive time: ?800 ms
> ? ? ? ?rx bytes: ? ? ? 670383000
> ? ? ? ?rx packets: ? ? 442114
> ? ? ? ?tx bytes: ? ? ? 18396981
> ? ? ? ?tx packets: ? ? 218811
> ? ? ? ?signal: ? ? ? ? -86 dBm
> ? ? ? ?tx bitrate: ? ? 12.0 MBit/s
> ? ? ? ?mesh llid: ? ? ?57085
> ? ? ? ?mesh plid: ? ? ?19775
> ? ? ? ?mesh plink: ? ? ESTAB
> _______________________________________________
> ath9k-devel mailing list
> ath9k-devel at lists.ath9k.org
> https://lists.ath9k.org/mailman/listinfo/ath9k-devel
>

Hi Marco,

I faced the same problem and I solved this issue with this simple patch:

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
---
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -2817,8 +2817,10 @@
 	}

 skip_chan_change:
-	if (changed & IEEE80211_CONF_CHANGE_POWER)
+	if (changed & IEEE80211_CONF_CHANGE_POWER) {
 		sc->config.txpowlimit = 2 * conf->power_level;
+		ath_update_txpow(sc);
+	}

 	spin_lock_bh(&sc->wiphy_lock);
 	disable_radio = ath9k_all_wiphys_idle(sc);


Now "iwconfig wlan0 txpower" works fine.

Regards.

Lorenzo

[ath9k-devel] weak signal strength using ar928x

[Porsch, Marco]

>>> Hello list,
>>
>>> i'm experiencing a very weak signal strength using ath9k and ar928x wireless in a wndr3700 router. I placed two of these approximately 3 meters line of sight of each other, and see signal strength of about -90dbm in mesh mode [1].
>>> The problem counts for sending and receiving, also in bss-mode. I posed my laptop approximately one meter away from the router as ap and measured the signal strength of the netgear firmware (openwrt 7.x with propietary driver) and openwrt (compat-wireless-2010-01-11, compat-wireless-2009-12-05), which gives me 20dbm difference [2].
>>> Using 'iwlist scan', original firmware shows 14 APs in my neighbourhood, openwrt shows 4.
>>
>> [...]
>>
>> I have taken a further look into the problem and realized, that 'iwconfig txpower' has no affect to the signal strength. I also tried up-down or scanning after change.
>> A test with hacked 'regd.c' (all set to 30dBm, no further limitations) also showed no changes in signal quality. Power management is off.
>>
>> A interesting detail is, that 5GHz (channel 52) also has quiet limited range, but far better than 2,4GHz. 5GHz txpower is set to 30dBm by default.
>>
>> Kernel is Linux OpenWrt 2.6.30.10 #10 Fri Jan 15 11:12:04 CET 2010 mips, wireless now from compat-wireless-2010-01-13.
>>
>>
>> Some debug outputs after 10min of iperf traffic over mesh-link between two identical wndr3700. I have seen no other 5GHz wifi in range.
>> 1) 3 meters line of sight
>> 2) 10 meters with thin glass/metal walls
>>   (in both cases 2,4GHz wont communicate at all)
>>
>>
>> 1)
>> [  3]  0.0-600.0 sec  1.27 GBytes  18.2 Mbits/sec
>>
>> cat /sys/kernel/debug/ath9k/phy1/rcstat
>>    HT    MCS   Rate    Success    Retries   XRetries        PER
>>                6.0:          0          0          0          0
>>                9.0:          0          0          0          0
>>               12.0:          0          0          0          0
>>               18.0:          0          0          0          0
>>               24.0:          1          0          0          0
>>               36.0:          1          0          0          0
>>               48.0:        286         19          0          0
>>               54.0:    1160839     113918         26          7
>>
>> Station 00:24:b2:58:fb:54 (on imesh5g)
>>        inactive time:  570 ms
>>        rx bytes:       2907897221
>>        rx packets:     2001025
>>        tx bytes:       422706850
>>        tx packets:     1161637
>>        signal:         -67 dBm
>>        tx bitrate:     54.0 MBit/s
>>        mesh llid:      4935
>>        mesh plid:      19635
>>        mesh plink:     ESTAB
>>
>>
>> 2)
>> [  3]  0.0-600.0 sec    294 MBytes  4.11 Mbits/sec
>>
>> cat /sys/kernel/debug/ath9k/phy1/rcstat
>>    HT    MCS   Rate    Success    Retries   XRetries        PER
>>                6.0:       6936       7587       2100          0
>>                9.0:      17804      18453       5797          0
>>               12.0:     153370     112773      21194         13
>>               18.0:      40331     104799      45526         49
>>               24.0:         94       4822       7450         54
>>               36.0:          0         15         21         82
>>               48.0:          0          0          0          0
>>               54.0:          0          0          0          0
>>
>> Station 00:24:b2:58:fb:54 (on imesh5g)
>>        inactive time:  800 ms
>>        rx bytes:       670383000
>>        rx packets:     442114
>>        tx bytes:       18396981
>>        tx packets:     218811
>>        signal:         -86 dBm
>>        tx bitrate:     12.0 MBit/s
>>        mesh llid:      57085
>>        mesh plid:      19775
>>        mesh plink:     ESTAB

>Hi Marco,
>
>I faced the same problem and I solved this issue with this simple patch:
>
>Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
>---
>--- a/drivers/net/wireless/ath/ath9k/main.c
>+++ b/drivers/net/wireless/ath/ath9k/main.c
>@@ -2817,8 +2817,10 @@
>        }
>
> skip_chan_change:
>-       if (changed & IEEE80211_CONF_CHANGE_POWER)
>+       if (changed & IEEE80211_CONF_CHANGE_POWER) {
>                sc->config.txpowlimit = 2 * conf->power_level;
>+               ath_update_txpow(sc);
>+       }
>
>        spin_lock_bh(&sc->wiphy_lock);
>        disable_radio = ath9k_all_wiphys_idle(sc);
>
>
>Now "iwconfig wlan0 txpower" works fine.
>
>Regards.
>
>Lorenzo

Thanks for your reply,

I applied your patch, but unfortunately i still cannot change my txpower. Even after setting txpower to 0 or off the AP shows the same signal level in 'iwlist scan'.

Regards,
Marco

[ath9k-devel] weak signal strength using ar928x

[Luis R. Rodriguez]

On Fri, Jan 15, 2010 at 06:54:23AM -0800, Porsch, Marco wrote:
> >>> Hello list,
> >>
> >>> i'm experiencing a very weak signal strength using ath9k and ar928x wireless in a wndr3700 router. I placed two of these approximately 3 meters line of sight of each other, and see signal strength of about -90dbm in mesh mode [1].
> >>> The problem counts for sending and receiving, also in bss-mode. I posed my laptop approximately one meter away from the router as ap and measured the signal strength of the netgear firmware (openwrt 7.x with propietary driver) and openwrt (compat-wireless-2010-01-11, compat-wireless-2009-12-05), which gives me 20dbm difference [2].
> >>> Using 'iwlist scan', original firmware shows 14 APs in my neighbourhood, openwrt shows 4.
> >>
> >> [...]
> >>
> >> I have taken a further look into the problem and realized, that 'iwconfig txpower' has no affect to the signal strength. I also tried up-down or scanning after change.
> >> A test with hacked 'regd.c' (all set to 30dBm, no further limitations) also showed no changes in signal quality. Power management is off.
> >>
> >> A interesting detail is, that 5GHz (channel 52) also has quiet limited range, but far better than 2,4GHz. 5GHz txpower is set to 30dBm by default.
> >>
> >> Kernel is Linux OpenWrt 2.6.30.10 #10 Fri Jan 15 11:12:04 CET 2010 mips, wireless now from compat-wireless-2010-01-13.
> >>
> >>
> >> Some debug outputs after 10min of iperf traffic over mesh-link between two identical wndr3700. I have seen no other 5GHz wifi in range.
> >> 1) 3 meters line of sight
> >> 2) 10 meters with thin glass/metal walls
> >>   (in both cases 2,4GHz wont communicate at all)
> >>
> >>
> >> 1)
> >> [  3]  0.0-600.0 sec  1.27 GBytes  18.2 Mbits/sec
> >>
> >> cat /sys/kernel/debug/ath9k/phy1/rcstat
> >>    HT    MCS   Rate    Success    Retries   XRetries        PER
> >>                6.0:          0          0          0          0
> >>                9.0:          0          0          0          0
> >>               12.0:          0          0          0          0
> >>               18.0:          0          0          0          0
> >>               24.0:          1          0          0          0
> >>               36.0:          1          0          0          0
> >>               48.0:        286         19          0          0
> >>               54.0:    1160839     113918         26          7
> >>
> >> Station 00:24:b2:58:fb:54 (on imesh5g)
> >>        inactive time:  570 ms
> >>        rx bytes:       2907897221
> >>        rx packets:     2001025
> >>        tx bytes:       422706850
> >>        tx packets:     1161637
> >>        signal:         -67 dBm
> >>        tx bitrate:     54.0 MBit/s
> >>        mesh llid:      4935
> >>        mesh plid:      19635
> >>        mesh plink:     ESTAB
> >>
> >>
> >> 2)
> >> [  3]  0.0-600.0 sec    294 MBytes  4.11 Mbits/sec
> >>
> >> cat /sys/kernel/debug/ath9k/phy1/rcstat
> >>    HT    MCS   Rate    Success    Retries   XRetries        PER
> >>                6.0:       6936       7587       2100          0
> >>                9.0:      17804      18453       5797          0
> >>               12.0:     153370     112773      21194         13
> >>               18.0:      40331     104799      45526         49
> >>               24.0:         94       4822       7450         54
> >>               36.0:          0         15         21         82
> >>               48.0:          0          0          0          0
> >>               54.0:          0          0          0          0
> >>
> >> Station 00:24:b2:58:fb:54 (on imesh5g)
> >>        inactive time:  800 ms
> >>        rx bytes:       670383000
> >>        rx packets:     442114
> >>        tx bytes:       18396981
> >>        tx packets:     218811
> >>        signal:         -86 dBm
> >>        tx bitrate:     12.0 MBit/s
> >>        mesh llid:      57085
> >>        mesh plid:      19775
> >>        mesh plink:     ESTAB
> 
> >Hi Marco,
> >
> >I faced the same problem and I solved this issue with this simple patch:
> >
> >Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
> >---
> >--- a/drivers/net/wireless/ath/ath9k/main.c
> >+++ b/drivers/net/wireless/ath/ath9k/main.c
> >@@ -2817,8 +2817,10 @@
> >        }
> >
> > skip_chan_change:
> >-       if (changed & IEEE80211_CONF_CHANGE_POWER)
> >+       if (changed & IEEE80211_CONF_CHANGE_POWER) {
> >                sc->config.txpowlimit = 2 * conf->power_level;
> >+               ath_update_txpow(sc);
> >+       }
> >
> >        spin_lock_bh(&sc->wiphy_lock);
> >        disable_radio = ath9k_all_wiphys_idle(sc);
> >
> >
> >Now "iwconfig wlan0 txpower" works fine.
> >
> >Regards.
> >
> >Lorenzo
> 
> Thanks for your reply,
> 
> I applied your patch, but unfortunately i still cannot change my txpower. Even after setting txpower to 0 or off the AP shows the same signal level in 'iwlist scan'.

Please see the patch

http://bugzilla.kernel.org/attachment.cgi?id=23981
http://bugzilla.kernel.org/show_bug.cgi?id=14642

Power change is reported there to change after a scan, this patch
is supposed to fix that upon immediate tx power change but I never
got a report of its results.

Feel free to follow up on that bug report. If you have something
that can actually measure the output power that would be best.

  Luis

[ath9k-devel] weak signal strength using ar928x

[Lorenzo Bianconi]

> On Fri, Jan 15, 2010 at 06:54:23AM -0800, Porsch, Marco wrote:
>> >>> Hello list,
>> >>
>> >>> i'm experiencing a very weak signal strength using ath9k and ar928x wireless in a wndr3700 router. I placed two of these approximately 3 meters line of sight of each other, and see signal strength of about -90dbm in mesh mode [1].
>> >>> The problem counts for sending and receiving, also in bss-mode. I posed my laptop approximately one meter away from the router as ap and measured the signal strength of the netgear firmware (openwrt 7.x with propietary driver) and openwrt (compat-wireless-2010-01-11, compat-wireless-2009-12-05), which gives me 20dbm difference [2].
>> >>> Using 'iwlist scan', original firmware shows 14 APs in my neighbourhood, openwrt shows 4.
>> >>
>> >> [...]
>> >>
>> >> I have taken a further look into the problem and realized, that 'iwconfig txpower' has no affect to the signal strength. I also tried up-down or scanning after change.
>> >> A test with hacked 'regd.c' (all set to 30dBm, no further limitations) also showed no changes in signal quality. Power management is off.
>> >>
>> >> A interesting detail is, that 5GHz (channel 52) also has quiet limited range, but far better than 2,4GHz. 5GHz txpower is set to 30dBm by default.
>> >>
>> >> Kernel is Linux OpenWrt 2.6.30.10 #10 Fri Jan 15 11:12:04 CET 2010 mips, wireless now from compat-wireless-2010-01-13.
>> >>
>> >>
>> >> Some debug outputs after 10min of iperf traffic over mesh-link between two identical wndr3700. I have seen no other 5GHz wifi in range.
>> >> 1) 3 meters line of sight
>> >> 2) 10 meters with thin glass/metal walls
>> >> ? (in both cases 2,4GHz wont communicate at all)
>> >>
>> >>
>> >> 1)
>> >> [ ?3] ?0.0-600.0 sec ?1.27 GBytes ?18.2 Mbits/sec
>> >>
>> >> cat /sys/kernel/debug/ath9k/phy1/rcstat
>> >> ? ?HT ? ?MCS ? Rate ? ?Success ? ?Retries ? XRetries ? ? ? ?PER
>> >> ? ? ? ? ? ? ? ?6.0: ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
>> >> ? ? ? ? ? ? ? ?9.0: ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
>> >> ? ? ? ? ? ? ? 12.0: ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
>> >> ? ? ? ? ? ? ? 18.0: ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
>> >> ? ? ? ? ? ? ? 24.0: ? ? ? ? ?1 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
>> >> ? ? ? ? ? ? ? 36.0: ? ? ? ? ?1 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
>> >> ? ? ? ? ? ? ? 48.0: ? ? ? ?286 ? ? ? ? 19 ? ? ? ? ?0 ? ? ? ? ?0
>> >> ? ? ? ? ? ? ? 54.0: ? ?1160839 ? ? 113918 ? ? ? ? 26 ? ? ? ? ?7
>> >>
>> >> Station 00:24:b2:58:fb:54 (on imesh5g)
>> >> ? ? ? ?inactive time: ?570 ms
>> >> ? ? ? ?rx bytes: ? ? ? 2907897221
>> >> ? ? ? ?rx packets: ? ? 2001025
>> >> ? ? ? ?tx bytes: ? ? ? 422706850
>> >> ? ? ? ?tx packets: ? ? 1161637
>> >> ? ? ? ?signal: ? ? ? ? -67 dBm
>> >> ? ? ? ?tx bitrate: ? ? 54.0 MBit/s
>> >> ? ? ? ?mesh llid: ? ? ?4935
>> >> ? ? ? ?mesh plid: ? ? ?19635
>> >> ? ? ? ?mesh plink: ? ? ESTAB
>> >>
>> >>
>> >> 2)
>> >> [ ?3] ?0.0-600.0 sec ? ?294 MBytes ?4.11 Mbits/sec
>> >>
>> >> cat /sys/kernel/debug/ath9k/phy1/rcstat
>> >> ? ?HT ? ?MCS ? Rate ? ?Success ? ?Retries ? XRetries ? ? ? ?PER
>> >> ? ? ? ? ? ? ? ?6.0: ? ? ? 6936 ? ? ? 7587 ? ? ? 2100 ? ? ? ? ?0
>> >> ? ? ? ? ? ? ? ?9.0: ? ? ?17804 ? ? ?18453 ? ? ? 5797 ? ? ? ? ?0
>> >> ? ? ? ? ? ? ? 12.0: ? ? 153370 ? ? 112773 ? ? ?21194 ? ? ? ? 13
>> >> ? ? ? ? ? ? ? 18.0: ? ? ?40331 ? ? 104799 ? ? ?45526 ? ? ? ? 49
>> >> ? ? ? ? ? ? ? 24.0: ? ? ? ? 94 ? ? ? 4822 ? ? ? 7450 ? ? ? ? 54
>> >> ? ? ? ? ? ? ? 36.0: ? ? ? ? ?0 ? ? ? ? 15 ? ? ? ? 21 ? ? ? ? 82
>> >> ? ? ? ? ? ? ? 48.0: ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
>> >> ? ? ? ? ? ? ? 54.0: ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
>> >>
>> >> Station 00:24:b2:58:fb:54 (on imesh5g)
>> >> ? ? ? ?inactive time: ?800 ms
>> >> ? ? ? ?rx bytes: ? ? ? 670383000
>> >> ? ? ? ?rx packets: ? ? 442114
>> >> ? ? ? ?tx bytes: ? ? ? 18396981
>> >> ? ? ? ?tx packets: ? ? 218811
>> >> ? ? ? ?signal: ? ? ? ? -86 dBm
>> >> ? ? ? ?tx bitrate: ? ? 12.0 MBit/s
>> >> ? ? ? ?mesh llid: ? ? ?57085
>> >> ? ? ? ?mesh plid: ? ? ?19775
>> >> ? ? ? ?mesh plink: ? ? ESTAB
>>
>> >Hi Marco,
>> >
>> >I faced the same problem and I solved this issue with this simple patch:
>> >
>> >Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
>> >---
>> >--- a/drivers/net/wireless/ath/ath9k/main.c
>> >+++ b/drivers/net/wireless/ath/ath9k/main.c
>> >@@ -2817,8 +2817,10 @@
>> > ? ? ? ?}
>> >
>> > skip_chan_change:
>> >- ? ? ? if (changed & IEEE80211_CONF_CHANGE_POWER)
>> >+ ? ? ? if (changed & IEEE80211_CONF_CHANGE_POWER) {
>> > ? ? ? ? ? ? ? ?sc->config.txpowlimit = 2 * conf->power_level;
>> >+ ? ? ? ? ? ? ? ath_update_txpow(sc);
>> >+ ? ? ? }
>> >
>> > ? ? ? ?spin_lock_bh(&sc->wiphy_lock);
>> > ? ? ? ?disable_radio = ath9k_all_wiphys_idle(sc);
>> >
>> >
>> >Now "iwconfig wlan0 txpower" works fine.
>> >
>> >Regards.
>> >
>> >Lorenzo
>>
>> Thanks for your reply,
>>
>> I applied your patch, but unfortunately i still cannot change my txpower. Even after setting txpower to 0 or off the AP shows the same signal level in 'iwlist scan'.
>
> Please see the patch
>
> http://bugzilla.kernel.org/attachment.cgi?id=23981
> http://bugzilla.kernel.org/show_bug.cgi?id=14642
>
> Power change is reported there to change after a scan, this patch
> is supposed to fix that upon immediate tx power change but I never
> got a report of its results.
>
> Feel free to follow up on that bug report. If you have something
> that can actually measure the output power that would be best.
>
> ?Luis
> _______________________________________________
> ath9k-devel mailing list
> ath9k-devel at lists.ath9k.org
> https://lists.ath9k.org/mailman/listinfo/ath9k-devel
>

Hi Luis,

I tested this patch on two Ubiquiti Rocket M devices (AR9280 chipset)
in this simple network configuration:

Rocket1 <--wireless link--> Rocket2

I injected packets from kernel space using a VAP in monitor mode on Rocket1
and misured the Rx power through another VAP in monitor mode on
Rocket2 analyzing the RSSI information reported from the driver. I
obtained the relationship between the Rx power and the Tx one is quite
linear when the Tx power is in the range from 3dbm to 20dbm whereas I
got some unexpected results when I set lower Tx power values
(0dbm-2dbm)
Tomorrow I am going to test this patch in AP/STA mode.

Regards.

Lorenzo

[ath9k-devel] weak signal strength using ar928x

[Lorenzo Bianconi]

>> On Fri, Jan 15, 2010 at 06:54:23AM -0800, Porsch, Marco wrote:
>>> >>> Hello list,
>>> >>
>>> >>> i'm experiencing a very weak signal strength using ath9k and ar928x wireless in a wndr3700 router. I placed two of these approximately 3 meters line of sight of each other, and see signal strength of about -90dbm in mesh mode [1].
>>> >>> The problem counts for sending and receiving, also in bss-mode. I posed my laptop approximately one meter away from the router as ap and measured the signal strength of the netgear firmware (openwrt 7.x with propietary driver) and openwrt (compat-wireless-2010-01-11, compat-wireless-2009-12-05), which gives me 20dbm difference [2].
>>> >>> Using 'iwlist scan', original firmware shows 14 APs in my neighbourhood, openwrt shows 4.
>>> >>
>>> >> [...]
>>> >>
>>> >> I have taken a further look into the problem and realized, that 'iwconfig txpower' has no affect to the signal strength. I also tried up-down or scanning after change.
>>> >> A test with hacked 'regd.c' (all set to 30dBm, no further limitations) also showed no changes in signal quality. Power management is off.
>>> >>
>>> >> A interesting detail is, that 5GHz (channel 52) also has quiet limited range, but far better than 2,4GHz. 5GHz txpower is set to 30dBm by default.
>>> >>
>>> >> Kernel is Linux OpenWrt 2.6.30.10 #10 Fri Jan 15 11:12:04 CET 2010 mips, wireless now from compat-wireless-2010-01-13.
>>> >>
>>> >>
>>> >> Some debug outputs after 10min of iperf traffic over mesh-link between two identical wndr3700. I have seen no other 5GHz wifi in range.
>>> >> 1) 3 meters line of sight
>>> >> 2) 10 meters with thin glass/metal walls
>>> >> ? (in both cases 2,4GHz wont communicate at all)
>>> >>
>>> >>
>>> >> 1)
>>> >> [ ?3] ?0.0-600.0 sec ?1.27 GBytes ?18.2 Mbits/sec
>>> >>
>>> >> cat /sys/kernel/debug/ath9k/phy1/rcstat
>>> >> ? ?HT ? ?MCS ? Rate ? ?Success ? ?Retries ? XRetries ? ? ? ?PER
>>> >> ? ? ? ? ? ? ? ?6.0: ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
>>> >> ? ? ? ? ? ? ? ?9.0: ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
>>> >> ? ? ? ? ? ? ? 12.0: ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
>>> >> ? ? ? ? ? ? ? 18.0: ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
>>> >> ? ? ? ? ? ? ? 24.0: ? ? ? ? ?1 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
>>> >> ? ? ? ? ? ? ? 36.0: ? ? ? ? ?1 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
>>> >> ? ? ? ? ? ? ? 48.0: ? ? ? ?286 ? ? ? ? 19 ? ? ? ? ?0 ? ? ? ? ?0
>>> >> ? ? ? ? ? ? ? 54.0: ? ?1160839 ? ? 113918 ? ? ? ? 26 ? ? ? ? ?7
>>> >>
>>> >> Station 00:24:b2:58:fb:54 (on imesh5g)
>>> >> ? ? ? ?inactive time: ?570 ms
>>> >> ? ? ? ?rx bytes: ? ? ? 2907897221
>>> >> ? ? ? ?rx packets: ? ? 2001025
>>> >> ? ? ? ?tx bytes: ? ? ? 422706850
>>> >> ? ? ? ?tx packets: ? ? 1161637
>>> >> ? ? ? ?signal: ? ? ? ? -67 dBm
>>> >> ? ? ? ?tx bitrate: ? ? 54.0 MBit/s
>>> >> ? ? ? ?mesh llid: ? ? ?4935
>>> >> ? ? ? ?mesh plid: ? ? ?19635
>>> >> ? ? ? ?mesh plink: ? ? ESTAB
>>> >>
>>> >>
>>> >> 2)
>>> >> [ ?3] ?0.0-600.0 sec ? ?294 MBytes ?4.11 Mbits/sec
>>> >>
>>> >> cat /sys/kernel/debug/ath9k/phy1/rcstat
>>> >> ? ?HT ? ?MCS ? Rate ? ?Success ? ?Retries ? XRetries ? ? ? ?PER
>>> >> ? ? ? ? ? ? ? ?6.0: ? ? ? 6936 ? ? ? 7587 ? ? ? 2100 ? ? ? ? ?0
>>> >> ? ? ? ? ? ? ? ?9.0: ? ? ?17804 ? ? ?18453 ? ? ? 5797 ? ? ? ? ?0
>>> >> ? ? ? ? ? ? ? 12.0: ? ? 153370 ? ? 112773 ? ? ?21194 ? ? ? ? 13
>>> >> ? ? ? ? ? ? ? 18.0: ? ? ?40331 ? ? 104799 ? ? ?45526 ? ? ? ? 49
>>> >> ? ? ? ? ? ? ? 24.0: ? ? ? ? 94 ? ? ? 4822 ? ? ? 7450 ? ? ? ? 54
>>> >> ? ? ? ? ? ? ? 36.0: ? ? ? ? ?0 ? ? ? ? 15 ? ? ? ? 21 ? ? ? ? 82
>>> >> ? ? ? ? ? ? ? 48.0: ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
>>> >> ? ? ? ? ? ? ? 54.0: ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0 ? ? ? ? ?0
>>> >>
>>> >> Station 00:24:b2:58:fb:54 (on imesh5g)
>>> >> ? ? ? ?inactive time: ?800 ms
>>> >> ? ? ? ?rx bytes: ? ? ? 670383000
>>> >> ? ? ? ?rx packets: ? ? 442114
>>> >> ? ? ? ?tx bytes: ? ? ? 18396981
>>> >> ? ? ? ?tx packets: ? ? 218811
>>> >> ? ? ? ?signal: ? ? ? ? -86 dBm
>>> >> ? ? ? ?tx bitrate: ? ? 12.0 MBit/s
>>> >> ? ? ? ?mesh llid: ? ? ?57085
>>> >> ? ? ? ?mesh plid: ? ? ?19775
>>> >> ? ? ? ?mesh plink: ? ? ESTAB
>>>
>>> >Hi Marco,
>>> >
>>> >I faced the same problem and I solved this issue with this simple patch:
>>> >
>>> >Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
>>> >---
>>> >--- a/drivers/net/wireless/ath/ath9k/main.c
>>> >+++ b/drivers/net/wireless/ath/ath9k/main.c
>>> >@@ -2817,8 +2817,10 @@
>>> > ? ? ? ?}
>>> >
>>> > skip_chan_change:
>>> >- ? ? ? if (changed & IEEE80211_CONF_CHANGE_POWER)
>>> >+ ? ? ? if (changed & IEEE80211_CONF_CHANGE_POWER) {
>>> > ? ? ? ? ? ? ? ?sc->config.txpowlimit = 2 * conf->power_level;
>>> >+ ? ? ? ? ? ? ? ath_update_txpow(sc);
>>> >+ ? ? ? }
>>> >
>>> > ? ? ? ?spin_lock_bh(&sc->wiphy_lock);
>>> > ? ? ? ?disable_radio = ath9k_all_wiphys_idle(sc);
>>> >
>>> >
>>> >Now "iwconfig wlan0 txpower" works fine.
>>> >
>>> >Regards.
>>> >
>>> >Lorenzo
>>>
>>> Thanks for your reply,
>>>
>>> I applied your patch, but unfortunately i still cannot change my txpower. Even after setting txpower to 0 or off the AP shows the same signal level in 'iwlist scan'.
>>
>> Please see the patch
>>
>> http://bugzilla.kernel.org/attachment.cgi?id=23981
>> http://bugzilla.kernel.org/show_bug.cgi?id=14642
>>
>> Power change is reported there to change after a scan, this patch
>> is supposed to fix that upon immediate tx power change but I never
>> got a report of its results.
>>
>> Feel free to follow up on that bug report. If you have something
>> that can actually measure the output power that would be best.
>>
>> ?Luis
>> _______________________________________________
>> ath9k-devel mailing list
>> ath9k-devel at lists.ath9k.org
>> https://lists.ath9k.org/mailman/listinfo/ath9k-devel
>>
>
> Hi Luis,
>
> I tested this patch on two Ubiquiti Rocket M devices (AR9280 chipset)
> in this simple network configuration:
>
> Rocket1 <--wireless link--> Rocket2
>
> I injected packets from kernel space using a VAP in monitor mode on Rocket1
> and misured the Rx power through another VAP in monitor mode on
> Rocket2 analyzing the RSSI information reported from the driver. I
> obtained the relationship between the Rx power and the Tx one is quite
> linear when the Tx power is in the range from 3dbm to 20dbm whereas I
> got some unexpected results when I set lower Tx power values
> (0dbm-2dbm)
> Tomorrow I am going to test this patch in AP/STA mode.
>
> Regards.
>
> Lorenzo
>

Hi Luis,

I carried out some tests in order to verify if this patch works fine
also in AP/STA mode.
Here is my topology:

AP = PC Engines Wrap with the latest version of OpenWRT trunk
(compat-wireless-2010-01-15)
and MikroTik Router Board R2n (Atheros AR9223 chipset) as miniPCI card

STA = Dell Studio XPS 13 (Intel Core 2 Duo P8700, 4096MB SDRAM DDR3)
with Debian Lenny (kernel 2.6.32.3) and wireless Dell 1515 (Atheros
AR9280 chipset)

STA <--Wireless link--> AP

I gradually decreased the Tx power on the AP and I measured the Rx one
through the information reported by Wicd on my Dell laptop.
I obtained these results:

1) iwconfig wlan0 txpower 20 ---> Rx power -37dbm
2) iwconfig wlan0 txpower 15 ---> Rx power -41dbm
3) iwconfig wlan0 txpower 10 ---> Rx power -45dbm
4) iwconfig wlan0 txpower 5 ---> Rx power -51dbm
5) iwconfig wlan0 txpower 0 ---> Rx power -37dbm ????

Ignoring the unexpected behavior I obtained in the latest test,
in my opinion this patch works correctly.

Regards.

Lorenzo

[ath9k-devel] weak signal strength using ar928x

[Porsch, Marco]

>> On Fri, Jan 15, 2010 at 06:54:23AM -0800, Porsch, Marco wrote:
>>> >>> Hello list,
>>> >>
>>> >>> i'm experiencing a very weak signal strength using ath9k and ar928x wireless in a wndr3700 router. I placed two of these approximately 3 meters line of sight of each other, and see signal strength of about -90dbm in mesh mode [1].
>>> >>> The problem counts for sending and receiving, also in bss-mode. I posed my laptop approximately one meter away from the router as ap and measured the signal strength of the netgear firmware (openwrt 7.x with propietary driver) and openwrt (compat-wireless-2010-01-11, compat-wireless-2009-12-05), which gives me 20dbm difference [2].
>>> >>> Using 'iwlist scan', original firmware shows 14 APs in my neighbourhood, openwrt shows 4.
>>> >>
>>> >> [...]
>>> >>
>>> >> I have taken a further look into the problem and realized, that 'iwconfig txpower' has no affect to the signal strength. I also tried up-down or scanning after change.
>>> >> A test with hacked 'regd.c' (all set to 30dBm, no further limitations) also showed no changes in signal quality. Power management is off.
>>> >>
>>> >> A interesting detail is, that 5GHz (channel 52) also has quiet limited range, but far better than 2,4GHz. 5GHz txpower is set to 30dBm by default.
>>> >>
>>> >> Kernel is Linux OpenWrt 2.6.30.10 #10 Fri Jan 15 11:12:04 CET 2010 mips, wireless now from compat-wireless-2010-01-13.
>>> >>
>>> >>
>>> >> Some debug outputs after 10min of iperf traffic over mesh-link between two identical wndr3700. I have seen no other 5GHz wifi in range.
>>> >> 1) 3 meters line of sight
>>> >> 2) 10 meters with thin glass/metal walls
>>> >>   (in both cases 2,4GHz wont communicate at all)
>>> >>
>>> >>
>>> >> 1)
>>> >> [  3]  0.0-600.0 sec  1.27 GBytes  18.2 Mbits/sec
>>> >>
>>> >> cat /sys/kernel/debug/ath9k/phy1/rcstat
>>> >>    HT    MCS   Rate    Success    Retries   XRetries        PER
>>> >>                6.0:          0          0          0          0
>>> >>                9.0:          0          0          0          0
>>> >>               12.0:          0          0          0          0
>>> >>               18.0:          0          0          0          0
>>> >>               24.0:          1          0          0          0
>>> >>               36.0:          1          0          0          0
>>> >>               48.0:        286         19          0          0
>>> >>               54.0:    1160839     113918         26          7
>>> >>
>>> >> Station 00:24:b2:58:fb:54 (on imesh5g)
>>> >>        inactive time:  570 ms
>>> >>        rx bytes:       2907897221
>>> >>        rx packets:     2001025
>>> >>        tx bytes:       422706850
>>> >>        tx packets:     1161637
>>> >>        signal:         -67 dBm
>>> >>        tx bitrate:     54.0 MBit/s
>>> >>        mesh llid:      4935
>>> >>        mesh plid:      19635
>>> >>        mesh plink:     ESTAB
>>> >>
>>> >>
>>> >> 2)
>>> >> [  3]  0.0-600.0 sec    294 MBytes  4.11 Mbits/sec
>>> >>
>>> >> cat /sys/kernel/debug/ath9k/phy1/rcstat
>>> >>    HT    MCS   Rate    Success    Retries   XRetries        PER
>>> >>                6.0:       6936       7587       2100          0
>>> >>                9.0:      17804      18453       5797          0
>>> >>               12.0:     153370     112773      21194         13
>>> >>               18.0:      40331     104799      45526         49
>>> >>               24.0:         94       4822       7450         54
>>> >>               36.0:          0         15         21         82
>>> >>               48.0:          0          0          0          0
>>> >>               54.0:          0          0          0          0
>>> >>
>>> >> Station 00:24:b2:58:fb:54 (on imesh5g)
>>> >>        inactive time:  800 ms
>>> >>        rx bytes:       670383000
>>> >>        rx packets:     442114
>>> >>        tx bytes:       18396981
>>> >>        tx packets:     218811
>>> >>        signal:         -86 dBm
>>> >>        tx bitrate:     12.0 MBit/s
>>> >>        mesh llid:      57085
>>> >>        mesh plid:      19775
>>> >>        mesh plink:     ESTAB
>>>
>>> >Hi Marco,
>>> >
>>> >I faced the same problem and I solved this issue with this simple patch:
>>> >
>>> >Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
>>> >---
>>> >--- a/drivers/net/wireless/ath/ath9k/main.c
>>> >+++ b/drivers/net/wireless/ath/ath9k/main.c
>>> >@@ -2817,8 +2817,10 @@
>>> >        }
>>> >
>>> > skip_chan_change:
>>> >-       if (changed & IEEE80211_CONF_CHANGE_POWER)
>>> >+       if (changed & IEEE80211_CONF_CHANGE_POWER) {
>>> >                sc->config.txpowlimit = 2 * conf->power_level;
>>> >+               ath_update_txpow(sc);
>>> >+       }
>>> >
>>> >        spin_lock_bh(&sc->wiphy_lock);
>>> >        disable_radio = ath9k_all_wiphys_idle(sc);
>>> >
>>> >
>>> >Now "iwconfig wlan0 txpower" works fine.
>>> >
>>> >Regards.
>>> >
>>> >Lorenzo
>>>
>>> Thanks for your reply,
>>>
>>> I applied your patch, but unfortunately i still cannot change my txpower. Even after setting txpower to 0 or off the AP shows the same signal level in 'iwlist scan'.
>>
>> Please see the patch
>>
>> http://bugzilla.kernel.org/attachment.cgi?id=23981
>> http://bugzilla.kernel.org/show_bug.cgi?id=14642
>>
>> Power change is reported there to change after a scan, this patch
>> is supposed to fix that upon immediate tx power change but I never
>> got a report of its results.
>>
>> Feel free to follow up on that bug report. If you have something
>> that can actually measure the output power that would be best.
>>
>>  Luis
>> _______________________________________________
>> ath9k-devel mailing list
>> ath9k-devel at lists.ath9k.org
>> https://lists.ath9k.org/mailman/listinfo/ath9k-devel
>>
>
> Hi Luis,
>
> I tested this patch on two Ubiquiti Rocket M devices (AR9280 chipset)
> in this simple network configuration:
>
> Rocket1 <--wireless link--> Rocket2
>
> I injected packets from kernel space using a VAP in monitor mode on Rocket1
> and misured the Rx power through another VAP in monitor mode on
> Rocket2 analyzing the RSSI information reported from the driver. I
> obtained the relationship between the Rx power and the Tx one is quite
> linear when the Tx power is in the range from 3dbm to 20dbm whereas I
> got some unexpected results when I set lower Tx power values
> (0dbm-2dbm)
> Tomorrow I am going to test this patch in AP/STA mode.
>
> Regards.
>
> Lorenzo
>

Hi Luis,

I carried out some tests in order to verify if this patch works fine
also in AP/STA mode.
Here is my topology:

AP = PC Engines Wrap with the latest version of OpenWRT trunk
(compat-wireless-2010-01-15)
and MikroTik Router Board R2n (Atheros AR9223 chipset) as miniPCI card

STA = Dell Studio XPS 13 (Intel Core 2 Duo P8700, 4096MB SDRAM DDR3)
with Debian Lenny (kernel 2.6.32.3) and wireless Dell 1515 (Atheros
AR9280 chipset)

STA <--Wireless link--> AP

I gradually decreased the Tx power on the AP and I measured the Rx one
through the information reported by Wicd on my Dell laptop.
I obtained these results:

1) iwconfig wlan0 txpower 20 ---> Rx power -37dbm
2) iwconfig wlan0 txpower 15 ---> Rx power -41dbm
3) iwconfig wlan0 txpower 10 ---> Rx power -45dbm
4) iwconfig wlan0 txpower 5 ---> Rx power -51dbm
5) iwconfig wlan0 txpower 0 ---> Rx power -37dbm ????

Ignoring the unexpected behavior I obtained in the latest test,
in my opinion this patch works correctly.

Regards.

Lorenzo






I did 'make clean' and rebuild and now the patch seems seems to be working.

I can fully confirm Lorenzos measurements, also the anomaly for 0dBm:
Notebook with intel 2200bg <---> router as AP
I am measuring with the Notebook and varying the txpower for the AP.

txpower          signal
20                  -55
10                  -62
5                    -65
0                    -55 (?)

This has however not solved my problem with the minimal range.

Regards,
Marco

[ath9k-devel] weak signal strength using ar928x

[Luis R. Rodriguez]

On Sun, Jan 17, 2010 at 02:29:20PM -0800, Lorenzo Bianconi wrote:
> >> On Fri, Jan 15, 2010 at 06:54:23AM -0800, Porsch, Marco wrote:
> >>> >>> Hello list,
> >>> >>
> >>> >>> i'm experiencing a very weak signal strength using ath9k and ar928x wireless in a wndr3700 router. I placed two of these approximately 3 meters line of sight of each other, and see signal strength of about -90dbm in mesh mode [1].
> >>> >>> The problem counts for sending and receiving, also in bss-mode. I posed my laptop approximately one meter away from the router as ap and measured the signal strength of the netgear firmware (openwrt 7.x with propietary driver) and openwrt (compat-wireless-2010-01-11, compat-wireless-2009-12-05), which gives me 20dbm difference [2].
> >>> >>> Using 'iwlist scan', original firmware shows 14 APs in my neighbourhood, openwrt shows 4.
> >>> >>
> >>> >> [...]
> >>> >>
> >>> >> I have taken a further look into the problem and realized, that 'iwconfig txpower' has no affect to the signal strength. I also tried up-down or scanning after change.
> >>> >> A test with hacked 'regd.c' (all set to 30dBm, no further limitations) also showed no changes in signal quality. Power management is off.
> >>> >>
> >>> >> A interesting detail is, that 5GHz (channel 52) also has quiet limited range, but far better than 2,4GHz. 5GHz txpower is set to 30dBm by default.
> >>> >>
> >>> >> Kernel is Linux OpenWrt 2.6.30.10 #10 Fri Jan 15 11:12:04 CET 2010 mips, wireless now from compat-wireless-2010-01-13.
> >>> >>
> >>> >>
> >>> >> Some debug outputs after 10min of iperf traffic over mesh-link between two identical wndr3700. I have seen no other 5GHz wifi in range.
> >>> >> 1) 3 meters line of sight
> >>> >> 2) 10 meters with thin glass/metal walls
> >>> >>   (in both cases 2,4GHz wont communicate at all)
> >>> >>
> >>> >>
> >>> >> 1)
> >>> >> [  3]  0.0-600.0 sec  1.27 GBytes  18.2 Mbits/sec
> >>> >>
> >>> >> cat /sys/kernel/debug/ath9k/phy1/rcstat
> >>> >>    HT    MCS   Rate    Success    Retries   XRetries        PER
> >>> >>                6.0:          0          0          0          0
> >>> >>                9.0:          0          0          0          0
> >>> >>               12.0:          0          0          0          0
> >>> >>               18.0:          0          0          0          0
> >>> >>               24.0:          1          0          0          0
> >>> >>               36.0:          1          0          0          0
> >>> >>               48.0:        286         19          0          0
> >>> >>               54.0:    1160839     113918         26          7
> >>> >>
> >>> >> Station 00:24:b2:58:fb:54 (on imesh5g)
> >>> >>        inactive time:  570 ms
> >>> >>        rx bytes:       2907897221
> >>> >>        rx packets:     2001025
> >>> >>        tx bytes:       422706850
> >>> >>        tx packets:     1161637
> >>> >>        signal:         -67 dBm
> >>> >>        tx bitrate:     54.0 MBit/s
> >>> >>        mesh llid:      4935
> >>> >>        mesh plid:      19635
> >>> >>        mesh plink:     ESTAB
> >>> >>
> >>> >>
> >>> >> 2)
> >>> >> [  3]  0.0-600.0 sec    294 MBytes  4.11 Mbits/sec
> >>> >>
> >>> >> cat /sys/kernel/debug/ath9k/phy1/rcstat
> >>> >>    HT    MCS   Rate    Success    Retries   XRetries        PER
> >>> >>                6.0:       6936       7587       2100          0
> >>> >>                9.0:      17804      18453       5797          0
> >>> >>               12.0:     153370     112773      21194         13
> >>> >>               18.0:      40331     104799      45526         49
> >>> >>               24.0:         94       4822       7450         54
> >>> >>               36.0:          0         15         21         82
> >>> >>               48.0:          0          0          0          0
> >>> >>               54.0:          0          0          0          0
> >>> >>
> >>> >> Station 00:24:b2:58:fb:54 (on imesh5g)
> >>> >>        inactive time:  800 ms
> >>> >>        rx bytes:       670383000
> >>> >>        rx packets:     442114
> >>> >>        tx bytes:       18396981
> >>> >>        tx packets:     218811
> >>> >>        signal:         -86 dBm
> >>> >>        tx bitrate:     12.0 MBit/s
> >>> >>        mesh llid:      57085
> >>> >>        mesh plid:      19775
> >>> >>        mesh plink:     ESTAB
> >>>
> >>> >Hi Marco,
> >>> >
> >>> >I faced the same problem and I solved this issue with this simple patch:
> >>> >
> >>> >Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
> >>> >---
> >>> >--- a/drivers/net/wireless/ath/ath9k/main.c
> >>> >+++ b/drivers/net/wireless/ath/ath9k/main.c
> >>> >@@ -2817,8 +2817,10 @@
> >>> >        }
> >>> >
> >>> > skip_chan_change:
> >>> >-       if (changed & IEEE80211_CONF_CHANGE_POWER)
> >>> >+       if (changed & IEEE80211_CONF_CHANGE_POWER) {
> >>> >                sc->config.txpowlimit = 2 * conf->power_level;
> >>> >+               ath_update_txpow(sc);
> >>> >+       }
> >>> >
> >>> >        spin_lock_bh(&sc->wiphy_lock);
> >>> >        disable_radio = ath9k_all_wiphys_idle(sc);
> >>> >
> >>> >
> >>> >Now "iwconfig wlan0 txpower" works fine.
> >>> >
> >>> >Regards.
> >>> >
> >>> >Lorenzo
> >>>
> >>> Thanks for your reply,
> >>>
> >>> I applied your patch, but unfortunately i still cannot change my txpower. Even after setting txpower to 0 or off the AP shows the same signal level in 'iwlist scan'.
> >>
> >> Please see the patch
> >>
> >> http://bugzilla.kernel.org/attachment.cgi?id=23981
> >> http://bugzilla.kernel.org/show_bug.cgi?id=14642
> >>
> >> Power change is reported there to change after a scan, this patch
> >> is supposed to fix that upon immediate tx power change but I never
> >> got a report of its results.
> >>
> >> Feel free to follow up on that bug report. If you have something
> >> that can actually measure the output power that would be best.
> >>
> >>  Luis
> >> _______________________________________________
> >> ath9k-devel mailing list
> >> ath9k-devel at lists.ath9k.org
> >> https://lists.ath9k.org/mailman/listinfo/ath9k-devel
> >>
> >
> > Hi Luis,
> >
> > I tested this patch on two Ubiquiti Rocket M devices (AR9280 chipset)
> > in this simple network configuration:
> >
> > Rocket1 <--wireless link--> Rocket2
> >
> > I injected packets from kernel space using a VAP in monitor mode on Rocket1
> > and misured the Rx power through another VAP in monitor mode on
> > Rocket2 analyzing the RSSI information reported from the driver. I
> > obtained the relationship between the Rx power and the Tx one is quite
> > linear when the Tx power is in the range from 3dbm to 20dbm whereas I
> > got some unexpected results when I set lower Tx power values
> > (0dbm-2dbm)
> > Tomorrow I am going to test this patch in AP/STA mode.
> >
> > Regards.
> >
> > Lorenzo
> >
> 
> Hi Luis,
> 
> I carried out some tests in order to verify if this patch works fine
> also in AP/STA mode.
> Here is my topology:
> 
> AP = PC Engines Wrap with the latest version of OpenWRT trunk
> (compat-wireless-2010-01-15)
> and MikroTik Router Board R2n (Atheros AR9223 chipset) as miniPCI card
> 
> STA = Dell Studio XPS 13 (Intel Core 2 Duo P8700, 4096MB SDRAM DDR3)
> with Debian Lenny (kernel 2.6.32.3) and wireless Dell 1515 (Atheros
> AR9280 chipset)
> 
> STA <--Wireless link--> AP
> 
> I gradually decreased the Tx power on the AP and I measured the Rx one
> through the information reported by Wicd on my Dell laptop.
> I obtained these results:
> 
> 1) iwconfig wlan0 txpower 20 ---> Rx power -37dbm
> 2) iwconfig wlan0 txpower 15 ---> Rx power -41dbm
> 3) iwconfig wlan0 txpower 10 ---> Rx power -45dbm
> 4) iwconfig wlan0 txpower 5 ---> Rx power -51dbm
> 5) iwconfig wlan0 txpower 0 ---> Rx power -37dbm ????
> 
> Ignoring the unexpected behavior I obtained in the latest test,
> in my opinion this patch works correctly.

Thanks Lorenzo I'll submit this upstream now, the 0 txpower anomoly can
be addressed separately.

  Luis

[ath9k-devel] weak signal strength using ar928x

[Goo Mail]

All,

On Fri, Jan 15, 2010 at 06:54:23AM -0800, Porsch, Marco wrote:

> i'm experiencing a very weak signal strength using ath9k and ar928x wireless in a wndr3700 router. I placed
>two of these approximately 3 meters line of sight of each other, and see signal strength of about -90dbm in
> mesh mode [1]. The problem counts for sending and receiving, also in bss-mode. I posed my laptop
> approximately one meter away from the router as ap and measured the signal strength

I have been seeing very similar problems to Marco's with my WNDR3700.
Does anyone on the list have suggestions on how to attack this
problem? Signal strength for me is anemic at best, and I see poor
levels when trying to either connect to remote APs, or to connect to
the WNDR3700 from another device when the router is in access point
mode.

As viewed from another device, the WNDR's signal strength is about 30
dB lower (in 2.4 GHz mode) compared to the manufacturer's firmware.

I am using the current OpenWRT trunk as of yesterday (19503), which
includes compat-wireless-2010-02-02. As far as I can tell, that
release includes the previously-mentioned txpower patch, although I
did not see any performance or range improvement between the pre-patch
and post-patch versions of the driver.

Any suggestions? Are there any types of debugging output that I can
post to the list, or programs that I could run, that would help us
figure out if this is a driver problem, an issue with the OpenWRT
distribution or configuration, or something else entirely?

Thanks,
Scott

[ath9k-devel] weak signal strength using ar928x

[RHS Linux User]

Hi,

   I am somewhat of a hardware hacker.   

   Sounds like a chip initialization problem to me.

   I would probably save a *LOT* of effort for everyone if 
someone had/created a GOOD reverse compiler for MIPS and
then decompiled the 'known to work well' driver for 
whatever chip!!

   There are probably a number of internal chip biases that need to be set
roughly right. Maybe just a switch or chip bug that takes some sort of
trick to initialize properly. 
 
   Just my humble opinion :)).

   

On Wed, 3 Feb 2010, Goo Mail wrote:

> All,
> 
> On Fri, Jan 15, 2010 at 06:54:23AM -0800, Porsch, Marco wrote:
> 
> > i'm experiencing a very weak signal strength using ath9k and ar928x wireless in a wndr3700 router. I placed
> >two of these approximately 3 meters line of sight of each other, and see signal strength of about -90dbm in
> > mesh mode [1]. The problem counts for sending and receiving, also in bss-mode. I posed my laptop
> > approximately one meter away from the router as ap and measured the signal strength
> 
> I have been seeing very similar problems to Marco's with my WNDR3700.
> Does anyone on the list have suggestions on how to attack this
> problem? Signal strength for me is anemic at best, and I see poor
> levels when trying to either connect to remote APs, or to connect to
> the WNDR3700 from another device when the router is in access point
> mode.
> 
> As viewed from another device, the WNDR's signal strength is about 30
> dB lower (in 2.4 GHz mode) compared to the manufacturer's firmware.
> 
> I am using the current OpenWRT trunk as of yesterday (19503), which
> includes compat-wireless-2010-02-02. As far as I can tell, that
> release includes the previously-mentioned txpower patch, although I
> did not see any performance or range improvement between the pre-patch
> and post-patch versions of the driver.
> 
> Any suggestions? Are there any types of debugging output that I can
> post to the list, or programs that I could run, that would help us
> figure out if this is a driver problem, an issue with the OpenWRT
> distribution or configuration, or something else entirely?
> 
> Thanks,
> Scott
> _______________________________________________
> ath9k-devel mailing list
> ath9k-devel at lists.ath9k.org
> https://lists.ath9k.org/mailman/listinfo/ath9k-devel
> 

[ath9k-devel] weak signal strength using ar928x

[Goo Mail]

Hello all,

>> On Fri, Jan 15, 2010 at 06:54:23AM -0800, Porsch, Marco wrote:
>>
>> > i'm experiencing a very weak signal strength using ath9k and ar928x wireless in a wndr3700 router. I placed
>> >two of these approximately 3 meters line of sight of each other, and see signal strength of about -90dbm in
>> > mesh mode [1]. The problem counts for sending and receiving, also in bss-mode. I posed my laptop
>> > approximately one meter away from the router as ap and measured the signal strength
>>
>> I have been seeing very similar problems to Marco's with my WNDR3700.
>> Does anyone on the list have suggestions on how to attack this problem?

I'm guessing that the main devs are busy and/or do not know the answer
to the above question. I was a radio DSP firmware engineer in a
previous life, so I'd like to pitch in and take a crack at it
myself--with the only problem being that I have been unable to find
any info on the chip.

Could anyone on the list point me to a copy of the datasheet(s) for
the ar928x series? I was unable to come up with anything with some
basic searches, so I hope that it is not under NDA. I can try to
muddle around with the sources, but debugging this problem seems like
it would be extraordinarily difficult without any documentation for
the radio interface.

Thanks!
Scott