From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 229CCECAAD3 for ; Sun, 11 Sep 2022 16:54:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229549AbiIKQyX (ORCPT ); Sun, 11 Sep 2022 12:54:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42348 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229578AbiIKQyW (ORCPT ); Sun, 11 Sep 2022 12:54:22 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EBA34220F7 for ; Sun, 11 Sep 2022 09:54:21 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id B21A6B80AFE for ; Sun, 11 Sep 2022 16:54:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7CFB6C433D6; Sun, 11 Sep 2022 16:54:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1662915259; bh=UlBl1VZr65IvLBgmS22N5ItDFO+Meetasxvgo56WKaQ=; h=References:From:To:Cc:Subject:Date:In-reply-to:From; b=TgdfaFeC13Q+QmcA12v1WVTFu72c5tnt87T6DMN1rqoq62YSIT+8WHJpPCpAC07nJ bTFL/oHcjVcBxBki+jxtUVnfxzM8YeyCoJxxV/7Fx7VNubQjkaZcEtFCzVpqF4YfFu PmR8ckuLqpFQ+2tyBd26xSs5XSWrkWEpCz6ILoNz/azsU+XhZMK1n1ffWLdm5/5YOF IEsaLDUh91Bn0C93KEJ7uy7GUlVMsR3mrwIPqjXDvkQ5YADxYkIWZbrXMassDnEn2f qZo2ddKH78xfObe3lpVdUKDgUoRYC1Ii30DMHn+cp3QZBIpeOpT90Ceyy4ey96xSyv MyTuAWLDb+/7g== References: User-agent: mu4e 1.8.9; emacs 28.1 From: Felipe Balbi To: Heikki Krogerus Cc: Daniel Martin , linux-usb@vger.kernel.org Subject: Re: dwc3: multiple ones and speed? Date: Sun, 11 Sep 2022 19:50:22 +0300 In-reply-to: Message-ID: <87leqp7sy3.fsf@balbi.sh> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Hi, Heikki Krogerus writes: > On Thu, Sep 08, 2022 at 10:51:00AM +0200, Daniel Martin wrote: >> Hi Heikki, >> >> `git blame drivers/usb/dwc3/dwc3-pci.c` said, that you might be the >> right person to ask. ;-) > > Felipe is the dwc3 driver and also the USB gadget subsystem > maintainer. I'll add him here, and also the linux-usb ml. > >> - Do you know of any device (preferably Intel x86_64) that has more >> than one dwc3 controller? >> - Do you have any speed comparisions for devices with a dwc3 acting in >> device mode (i. e. throughput and latency of a storage gadget)? > > I'm sorry I don't. But perhaps Felipe or someone else on the list has? I've been out of the Intel loop for quite some time, but IIRC some of the newest cores supporting USB 3.2 on the peripheral side were made so that SuperSpeed would be handled by one dwc3 instance and SuperSpeed Plus would be handled by another dwc3 instance altogether. >> I've got a few Rock Pi X at the moment, though its gadget performance >> isn't that satisfying and I don't know if the Cherry Trail Z8350 or >> the included dwc3 is the limiting factor. why would it be? Can you define "performance"? Which kernel version are you using? Have you tried latest tag from Linus? What gadget driver are you using? How have you configured it? Are you running HighSpeed or SuperSpeed? (IIRC, CherryTrail is superspeed only). -- balbi