Re: IWLWIFI - 3.18-stable

[Chris Clayton <chris2553@googlemail.com>]

Thanks Emmanuel.

On 01/11/15 14:16, Emmanuel Grumbach wrote:
> Hi Chris,
> 
> thank you for you analysis, it is very helpful
> 

You're welcome.

>> Doh! Cut and paste error ...
>>
>> On 01/11/15 12:56, Chris Clayton wrote:
>>> Hi Kalle,
>>>
>>> Having recently bought a new laptop, I've just started using the iwlwifi driver for wireless networking. I found both
>>> 3.18.x and the current development tree to be very unreliable due to frequent disconnections from the router.
>>>
>>> Before you merged them into your tree, I grabbed the latest fixes from iwlwifi-fixes tree and applied them to the
>>> development kernel. Since I did that I've had no problems at all with dropped connections. I then looked at each patch
>>> to see whether it might be applicable to 3.18 and found that two of them looked as if they should be useful. They are:
>>>
>>> c93edc639392df733c7d72db4376a9add775d18a - iwlwifi: mvm: don't allow diversity if BT Coex / TT forbid it
>>
>> The above should have been:
>>
>> c93edc639392df733c7d72db4376a9add775d18a - iwlwifi: mvm: fix Rx with both chains
>>
>>>
>>> a9dc5060bf3a32ac3dad472f15416054b92dc5b5 - iwlwifi: mvm: fix out of bounds access to tid_to_mac80211_ac
>>>
>>> With those two applied, I've had stable wireless networking on 3.18.2 and, more recently, 3.18.2. Consequently, they
>>> seem appropriate for tagging for 3.18-stable, but, as far as I can see, they haven't been tagged for stable. Apologies,
>>> if I'm mistaken, but if I'm not, could you consider submitting the two patches for inclusion in 3.18, please? Of course,
>>> they may be appropriate to earlier kernels too - I haven't looked.
>>>
> 
> The first one (c93edc639392df733c7d72db4376a9add775d18a) is tagged for stable.

Ah, sorry I missed that.

> Are you using bluetooth?

Yes, I have a bluetooth mouse and use bluetooth for audio from time to time.

> Are you able to tell me which of the two really helps?

It's c93edc639392df733c7d72db4376a9add775d18a that helps. With that applied, I can set off a task which, in a loop,
continually copies a 180MB file from a server on my network. The network remained stable for over 30 minutes before I
killed the task. Without the patch, the network fails during the first iteration of copying the file.

a9dc5060bf3a32ac3dad472f15416054b92dc5b5 doesn't seem to have any effect on the instability.


> Unless I am missing something, the first one
> (c93edc639392df733c7d72db4376a9add775d18a) should help only if you
> disabled power save. Is that the case?

Not that I know of. The only power-related thing in my init scripts is echoing 5 to /proc/sys/vm/laptop_mode, which I
believe configures disk activity to save power. The mouse does have a power saving feature, however. According to the
manual, it reduces its power consumption in steps the longer it is inactive. As I frequently work in kde's konsole
terminal application, mouse inactivity is common.

Hope this helps and feel free to request additional information.

Chris
>