Am 23.07.2015 um 10:08 schrieb wim torfs:
> 
> 
> On 07/22/2015 07:16 PM, Oleksij Rempel wrote:
>> Am 22.07.2015 um 18:37 schrieb Rolf Anderegg:
>>>
>>> On 16/07/15 13:54, Oleksij Rempel wrote:
>>>> Am 13.07.2015 um 13:52 schrieb Rolf Anderegg:
>>>>>
>>>>> I suspect that there are bandwidth/speed issues when dealing with USB
>>>>> adapters, but that does not inherently mean that the connection is
>>>>> prone
>>>>> to drop, right? Doesn't that mean that I am leaking packages somewhere
>>>>> along the way? What else could I be looking for?
>>>>
>>>> The packages can drop if you will do channel scan. STA mode need some
>>>> seconds to complete channel scan. It means AP will be all the time
>>>> unavailable.
>>>
>>> Ok, that may be. Then again why am I not experiencing the same
>>> connection drop on my ath5k setup? Because the channel scan is more
>>> likely to be completed in due time?
>>
>> Yes, channel scantime on usb device is match longer then on pci.
>>
> 
> May I ask for the reason it takes a longer time to complete the scanning
> on a USB device compared to a PCI device? I assume the internals of an
> ath9k PCI device is similar as that of an ath9k_htc USB device, so is it
> purely the bus speed that affects this time? Or is the USB device a
> smaller version of the chipset on the PCI device and therefore with a
> lower speed due to power concerns?
> 
> If it is due to the bus speed, would it be possible to decouple the
> scanning process from the bus, that is, I assume that the hardware
> performs all the necessary channel switching and channel sensing, so why
> not allow the hardware to gather such information and transfer the
> results in a single burst to the host over the USB bus? Or is the
> channel switching controlled by the host and it takes a lot of time due
> to the duration of transmitting the channel switching commands to the
> USB device?

Well, it is about development time vs scan time: do as match as possible
with one code base or develop two different code bases.

-- 
Regards,
Oleksij