carl9170 problem

carl9170 problem

[Dale Turner]

Hello everyone.

Thanks for releasing the carl9170 driver in the 
compat-wireless package. I have been able to compile the driver, so that
 is great. The connection seems to be a bit inconsistent. I get the 
following quite often in /var/log/messages :

kernel: ieee80211 phy9: channel change: 2472 -> 2462 failed (2)

and/or

kernel: ieee80211 phy9: invalid plcp cck rate (0)

and/or

kernel: ieee80211 phy9: FW: MAC RESET

When
 that happens (which can be as often as every few minutes) my reported 
connection speed in network manager drops to 6 or 1 Mb/s. The network 
speed is noticeably reduced (for instance download speeds drastically 
reduce, online videos stutter, or music streaming from a different 
computer pauses, etc).

My previous adapter TP-Link TL-WN721N (ath9k_htc driver) did not behave like this.

Any thoughts/solutions ??

Again, many thanks for providing the driver. I cannot program (I wish I could to help) but I can report my experience.

Dale

 		 	   		   		 	   		  

Re: carl9170 problem

[Christian Lamparter]

On Saturday 25 September 2010 02:34:26 Dale Turner wrote:
> 
> Hello everyone.
> 
> Thanks for releasing the carl9170 driver in the 
> compat-wireless package.
I recommend using wireless-testing.git over
compat-wireless + old kernel.

> I have been able to compile the driver, so that is great.
> The connection seems to be a bit inconsistent.
> I get the following quite often in /var/log/messages :

> kernel: ieee80211 phy9: channel change: 2472 -> 2462 failed (2)
That's a noise floor calibration error. Check if your compat-wireless
source  includes "carl9170: reinit phy after HT settings have changed".
Also check if there is another device active on the same (primary/
secondary) channel like a microwave oven, DECT phone or another wifi
network, or wifi network peer. 

> kernel: ieee80211 phy9: invalid plcp cck rate (0)
This is a known bug, the driver received a invalid stream frame
from the hardware. This only happens a lot when the AP ignores
the device's ampdu spacing.
(Do you have an older draft-n AP, if so what chip?)

> kernel: ieee80211 phy9: FW: MAC RESET
The device failed to send pending data for more than 150ms(HT40) - 300ms,
either because the medium was busy, or the AP failed to response at all
mostly because it has crashed first.
(check if your AP's TSF is no where near your AP's uptime)

> When
>  that happens (which can be as often as every few minutes) my reported 
> connection speed in network manager drops to 6 or 1 Mb/s. The network 
> speed is noticeably reduced (for instance download speeds drastically 
> reduce, online videos stutter, or music streaming from a different 
> computer pauses, etc).
Network manager has a feature called "background scanning".
The advantage is that you'll always have a up-to-date site survey.
The disadvantage is that it needs to perform a periodically scan
(as in every few minutes) which on some occasions result in a
channel change failed hiccup.

> 
> My previous adapter TP-Link TL-WN721N (ath9k_htc driver) did not behave like this.
Why did you go back to the previous generation? 
ath9k_htc (for AR9271) is in fact the replacement for AR9170.

Regards,
	Chr

Re: carl9170 problem

[Dale Turner]

>>> Hello everyone.
>>>
>>> Thanks for releasing the carl9170 driver in the
>>> compat-wireless package.
>> I recommend using wireless-testing.git over
>> compat-wireless + old kernel.
>>
>>> I have been able to compile the driver, so that is great.
>>> The connection seems to be a bit inconsistent.
>>> I get the following quite often in /var/log/messages :
>>
>>> kernel: ieee80211 phy9: channel change: 2472 -> 2462 failed (2)
>> That's a noise floor calibration error. Check if your compat-wireless
>> source includes "carl9170: reinit phy after HT settings have changed".
>> Also check if there is another device active on the same (primary/
>> secondary) channel like a microwave oven, DECT phone or another wifi
>> network, or wifi network peer.
>>
>>> kernel: ieee80211 phy9: invalid plcp cck rate (0)
>> This is a known bug, the driver received a invalid stream frame
>> from the hardware. This only happens a lot when the AP ignores
>> the device's ampdu spacing.
>> (Do you have an older draft-n AP, if so what chip?)
>>
>>> kernel: ieee80211 phy9: FW: MAC RESET
>> The device failed to send pending data for more than 150ms(HT40) - 300ms,
>> either because the medium was busy, or the AP failed to response at all
>> mostly because it has crashed first.
>> (check if your AP's TSF is no where near your AP's uptime)
>>
>>> When
>>> that happens (which can be as often as every few minutes) my reported
>>> connection speed in network manager drops to 6 or 1 Mb/s. The network
>>> speed is noticeably reduced (for instance download speeds drastically
>>> reduce, online videos stutter, or music streaming from a different
>>> computer pauses, etc).
>> Network manager has a feature called "background scanning".
>> The advantage is that you'll always have a up-to-date site survey.
>> The disadvantage is that it needs to perform a periodically scan
>> (as in every few minutes) which on some occasions result in a
>> channel change failed hiccup.
>>
>>>
>>> My previous adapter TP-Link TL-WN721N (ath9k_htc driver) did not behave like this.
>> Why did you go back to the previous generation?
>> ath9k_htc (for AR9271) is in fact the replacement for AR9170.
>>
>> Regards,
>> Chr
>  
Thanks for your response.
 
 I chose the TL-WN821N because it seemed to have a 'better' feature set (faster speed, MIMO, etc) plus the carl9170 driver is supposed to capable of AP mode. (I have plans in the future of constructing a wireless router). So I thought I was improving (guess I'm wrong).
 
 I don't think there are any nearby networks on my channel. I purposely change it from default ( 6 ) to 11 (actually wide 9). 
 
 The access point is a Linksys wrt120n (probably not the best, I know).
 
 To be honest, I don't know what a TSF is or how to check it.
 
 Thanks again,
 
 Dale

 		 	   		  

Re: carl9170 problem

[Christian Lamparter]

On Tuesday 28 September 2010 03:47:00 Dale Turner wrote:
> >> kernel: ieee80211 phy9: FW: MAC RESET
> > The device failed to send pending data for more than 150ms(HT40) - 300ms,
> > either because the medium was busy, or the AP failed to response at all
> > mostly because it has crashed first.
> > (check if your AP's TSF is no where near your AP's uptime)
> 
> I don't think there are any nearby networks on my channel.
> I purposely change it from default ( 6 ) to 11 (actually wide 9).
What's wide 9? HT40 with the primary channel on 11 and the extension
on 6?
 
> The access point is a Linksys wrt120n (probably not the best, I know).
Isn't this a 1-stream align-n (AR9285) platform? If so then there is
no advantage of using an AR9170 over the AR9271.

> To be honest, I don't know what a TSF is or how to check it.
The TSF keeps the timers for all STAs in the "network" synchronized.
http://en.wikipedia.org/wiki/Timing_Synchronization_Function_%28TSF%29

It can be easily check by: iw dev wlanX scan

e.g.: (sample output)
BSS 00:02:32:0d:d1:32 (on wlan13)
        TSF: 2669831323 usec (0d, 00:44:29) <-------
        freq: 2437

This will tell you that the "network" has an uptime of
0 days, 0 hours, 44 minutes and 29 seconds.

Regards,
	Chr