From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oleksij Rempel Date: Mon, 12 May 2014 16:47:30 +0200 Subject: [ath9k-devel] Stable Version for ath9k_htc in AP Mode? In-Reply-To: <20140512131119.30298.qmail@stuge.se> References: <5367E75D.1070601@rempel-privat.de> <53688D75.9040006@rempel-privat.de> <536DF0AF.1030306@rempel-privat.de> <53707FE6.3030204@rempel-privat.de> <20140512131119.30298.qmail@stuge.se> Message-ID: <5370DF02.2070808@rempel-privat.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ath9k-devel@lists.ath9k.org Am 12.05.2014 15:11, schrieb Peter Stuge: > Oleksij Rempel wrote: >> From dmesg i see that, to one USB 1.1 root-hub attached two device, >> ath9k_htc and GobiNet. GobiNet was recognised as eth1 + 3 x ttyUSB. >> IMO, it is a lot for one USB 1.1. > > True as that may be, if there is a bandwidth requirement for the > interface to function correctly and the USB protocol being used does > not guarantee that bandwidth (only control+interrupt transfers could > do it in a meaningful way, and they are rather low bandwidth) then > the USB stack would have to allow the driver to reserve bus time, and > the driver would have to make a reservation to successfully handle > worst-case load. > > That's not neccessarily a small change. :\ I tested ath9k-htc on many different usb host controllers (not usb 1.1), and noticed that most USB 2.0 controllers need some *msecs* to transfer one Interrupt package to the adapter or at least to get ACK signal. USB 3.0 was transferring same package in some *usecs*. The results should be similar for both controller, but it is not the case. Even different USB 2.0 controller was performing differently. This big difference is responsible for extremely long scan time on ath9k_htc on USB 2.0. Since Interrupt Endpoints are heavily used on this devices, reducing bandwidth and/or increasing transfer time for Interrupt traffic will be critical. Best indicator for this issue would be, disabling LED subsystem to get better stability. What, according to Aaron, is the case. -- Regards, Oleksij -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 278 bytes Desc: OpenPGP digital signature Url : http://lists.ath9k.org/pipermail/ath9k-devel/attachments/20140512/86dc4932/attachment.pgp