Re: [rt2x00-users] Poor performance and lockup with rt2800usb andAsus USB-N13 adapter
From: Robert Hancock
Date: Sat Dec 24 2011 - 20:21:21 EST
On Thu, Dec 22, 2011 at 10:18 AM, Stanislaw Gruszka <sgruszka@xxxxxxxxxx> wrote:
> On Tue, Dec 20, 2011 at 03:43:17PM +0100, Stanislaw Gruszka wrote:
>> I just discovered that at least some problems are related with power
>> save. After "iwconfig wlanX power off" I have pretty short ping times
>> and good throughput, both comparable with vendor driver. But I did not
>> check that on all adapters that I have yet.
>> Looking a bit more at that seem we stop and wake queues several times
>> between sending each frame. Looks like that thing need to be optimized
>> in mac80211, or some parameters have to be setup properly by rt2x00 ...
>> Also rt2800 PCI and SOC have PS disabled by default ...
> There is no bug with ping latencies when power save is enabled. Ping
> send packet every second, between that we put driver in power save
> mode (i.e. tell AP that we are sleeping and it has to buffer frame
> to us). When we send ping packet, we wake up and receive packet from
> a AP after longer time than in normal operation mode.
> I did more testing here and I have one device that works very bad,
> no matter if PS is configured or not. It is
> phy6 -> rt2x00_set_chip: Info - Chipset detected - rt: 3071, rf: 0008, rev: 021c.
> I'm going to investigate problems with that device, hopefully these are the
> same problems that Robert and Andreas have.
I confirmed that switching off power save doesn't improve the
performance significantly with the Asus USB-N13. I suspect that there
must be some difference between the 3070 device and the 3071/3072 that
affects this, since the 3070 device I have works much better.
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