Re: linux 3.2-rcX iwlwifi driver's problem (wifi link unstable when moving between multiple APs)

["Guy, Wey-Yi" <wey-yi.w.guy@intel.com>]

Hi Cheng,

On Tue, 2012-01-10 at 16:01 -0800, Cheng Renquan wrote:
> On Tue, Jan 10, 2012 at 2:27 PM, Guy, Wey-Yi <wey-yi.w.guy@intel.com> wrote:
> > Hi Cheng,
> >
> > On Tue, 2012-01-10 at 15:17 -0800, Cheng Renquan wrote:
> >> I've upgraded to Linux 3.2 and roaming failed randomly again,
> >>
> >> after the failure it may recover
> >> sometimes by switch off and on the wifi button on laptop,
> >> sometimes by "modprobe -r iwlwifi && modprobe iwlwifi",
> >> sometimes by "stop networkmanager and start networkmanager",
> >> sometimes recover automatically 10 or 20 minutes later,
> >> sometimes never recover, infinitely looping (can only move to other
> >> place, but same place has good wifi coverage verified by other
> >> colleagues, win/mac users)
> >>
> >>
> >> have checked it has your recent 78feb35 & 81670a4 commits,
> >> $ git log -n5 --no-merges --oneline v3.2 -- drivers/net/wireless/iwlwifi/
> >> 96f1f05 iwlwifi: update SCD BC table for all SCD queues
> >> 78feb35 iwlwifi: allow to switch to HT40 if not associated
> >> 81670a4 iwlwifi: tx_sync only on PAN context
> >> 123877b iwlwifi: do not set the sequence control bit is not needed
> >> 9995ffe iwlwifi: change the default behavior of watchdog timer
> >>
> > Are you saying without those two commits (78feb35 & 81670a4), the
> > roaming works?
> 
> No, the v3.2-rc6 which doesn't include (78feb35 & 81670a4) also has no
> roaming working,
> 
> The week before Xmas I tested v3.2-rc7 which include your (78feb35 &
> 81670a4) really has
> roaming working, roamed to new AP stable in 1 minute in most meeting
> rooms of the office,
> 
> Now this week 3.2 came out, since it has on changes under
> "drivers/net/wireless/iwlwifi/",
> I think it should be same with 3.2-rc7; but roaming not good again,
> and may go off even not moving, staying same place;
> 
> 
> [archuser@archtop linux-git]$ git log --no-merges -n5 --oneline
> v3.2-rc6 -- drivers/net/wireless/iwlwifi/
> 9995ffe iwlwifi: change the default behavior of watchdog timer
> 34a5b4b iwlwifi: do not re-configure HT40 after associated
> 274b89c iwlagn: fix HW crypto for TX-only keys
> 43e5885 iwlwifi: avoid a panic when unloading the module with RF Kill
> f956c34 iwlwifi: don't perform "echo test" when cmd queue stuck
> 
> [archuser@archtop linux-git]$ git log --no-merges -n5 --oneline
> v3.2-rc7 -- drivers/net/wireless/iwlwifi/
> 96f1f05 iwlwifi: update SCD BC table for all SCD queues
> 78feb35 iwlwifi: allow to switch to HT40 if not associated
> 81670a4 iwlwifi: tx_sync only on PAN context
> 123877b iwlwifi: do not set the sequence control bit is not needed
> 9995ffe iwlwifi: change the default behavior of watchdog timer
> 
> 
> The difference with that week before Xmas I think may be now the
> office has more people
> since everyone has come back from holidays;
> 
> In a 1hour meeting on Monday (yesterday) with 10+ people in a meeting room,
> every other user (win&mac) are online except me: trying get iwlwifi working,
> throughout all 60 minutes my iwlwifi get roaming looping cannot
> recover (tried all above methods)
> and when the meeting finished, other ones left, my iwlwifi started
> working; recovered in 60 minutes; how sad

Got it, very sorry for the problem you experience, yes, I agree with
you, it might be because the noisy environment. Could you please send me
the dmesg log with the following flags

$sudo modprobe iwlwifi debug=0x1083

Thanks
Wey