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 2ED46C7EE23 for ; Sun, 4 Jun 2023 20:11:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230072AbjFDULw (ORCPT ); Sun, 4 Jun 2023 16:11:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52682 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229449AbjFDULt (ORCPT ); Sun, 4 Jun 2023 16:11:49 -0400 Received: from mail-qv1-xf2f.google.com (mail-qv1-xf2f.google.com [IPv6:2607:f8b0:4864:20::f2f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 91456BD; Sun, 4 Jun 2023 13:11:47 -0700 (PDT) Received: by mail-qv1-xf2f.google.com with SMTP id 6a1803df08f44-6261a25e9b6so35160216d6.0; Sun, 04 Jun 2023 13:11:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1685909506; x=1688501506; h=in-reply-to:content-disposition:mime-version:references:reply-to :message-id:subject:cc:to:from:date:sender:from:to:cc:subject:date :message-id:reply-to; bh=V3EDFvKUzYSUh/h5wzvGG2N7/ZQahbS0m6rxVyrGrqU=; b=IDoMciNH8f1I843x2aVxm+/422tkCA46ZKLKBMptut5pakNhbvcXJyDdW+ACj6/rxt GjjIEF0Qubj5WGEdh5B4LWqhVXo5oNUJMXUxcGNY/+fSvG/e+r9rcVh+DeJfYnPg62pP 3FvwQqznII+hGK6SYd+dlaip2ddwNT4Y2srPiVjK2wPJu0zfLcsvRYARu4KHrbZPcCVB QpiCgP8OAN0ckvjmJKTR7QZcaPgdPzXp9GwfaRwQ4LvHxvfAecRqjILL1804X4FklWZt CgGfpGnu8OsDbPNIin4YDEuCQfW3XVKsq0k4aziCRcze9a3l5uKBMw8Ofx5JsVtr77AH 5bHg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685909506; x=1688501506; h=in-reply-to:content-disposition:mime-version:references:reply-to :message-id:subject:cc:to:from:date:sender:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=V3EDFvKUzYSUh/h5wzvGG2N7/ZQahbS0m6rxVyrGrqU=; b=XC+mxS96nEvGVUNsGgMsHJmIhAggM5hCvUoUsDotlAT0yx359/GYy8z8n/gUDPNwns mPQte5o9kkIJ2/W80dTgq2aDYLfPPk+5kqUkqzNa/fF89idMfQB5Ggmz8E/RDTbqU8t4 xBg2h+GU3uTbvDLAf+/PifJdSD4h97+plUX0S0Dtb0FGXwZwOAXK4rc76Gpbum/Njz8G 1CAwyjfM99q1s9FEMRvJrt5gm7T9akbtNgBxec2jFOliMCdBlhnz64WjxKP5x43xMb/s UEyQcd+8J2xIAABEMviCq9mP1LTvTxF7pvocALBvZAIczKr8fFDFJTabnMDYUgXuKunr kC4w== X-Gm-Message-State: AC+VfDyzZ6kXxdFQZ+celZSkfIvLCkUFwYXaDdw3YhX5jOVyo9LHWz4I HxlIXhUfAIpfIaVXXTNugvltVdrfLw== X-Google-Smtp-Source: ACHHUZ6KUBceOq83W12Chk+0PZ8J0HIVPf6Ln1cAmLkQI3vjoiikGgsobm7l0glPNrxAtfJWaECBbA== X-Received: by 2002:a05:6214:628:b0:625:aa1a:b6d9 with SMTP id a8-20020a056214062800b00625aa1ab6d9mr4565003qvx.59.1685909506607; Sun, 04 Jun 2023 13:11:46 -0700 (PDT) Received: from serve.minyard.net ([47.189.94.26]) by smtp.gmail.com with ESMTPSA id t11-20020a056214154b00b00626117620aasm3495811qvw.105.2023.06.04.13.11.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 04 Jun 2023 13:11:45 -0700 (PDT) Sender: Corey Minyard Received: from mail.minyard.net (unknown [IPv6:2001:470:b8f6:1b:40d3:18db:d1d3:341e]) by serve.minyard.net (Postfix) with ESMTPSA id B603D1800C3; Sun, 4 Jun 2023 20:11:44 +0000 (UTC) Date: Sun, 4 Jun 2023 15:11:43 -0500 From: Corey Minyard To: Johan Hovold Cc: Craig Shelley , Linux Kernel , linux-usb@vger.kernel.org Subject: Re: Break doesn't work on a CP2105 Message-ID: Reply-To: minyard@acm.org References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jun 04, 2023 at 02:17:16PM +0200, Johan Hovold wrote: > On Fri, Jun 02, 2023 at 11:46:56AM -0500, Corey Minyard wrote: > > On Fri, Jun 02, 2023 at 02:53:31PM +0200, Johan Hovold wrote: > > > > I just posted a patch series which does that. The USB serial drivers do > > > not currently return any errors related to break signalling even though > > > this has been possible since 2008. > > > > > > The same mechanism can be used to report that break signalling is not > > > supported by a device or driver, but the USB serial drivers would be the > > > first tty drivers that actually do this. If it turns out to cause any > > > trouble we can still use this series to avoid the unnecessary wait. > > > > > > Care to give the series a try? > > > > > > https://lore.kernel.org/lkml/20230602124642.19076-1-johan@kernel.org > > > > I have tested this series. I can verify that one of the CP2105 ports > > (ttyUSB0) does not return an error on sending the break, and the other > > (ttyUSB1) does. This is the only USB serial device on the system. > > Thanks for testing. > > > However, the device hooked to the remote console (ttyUSB0), the one not > > returning an error on sending a break, still doesn't send a break. So > > my problem isn't fixed :-(. > > > > # ls -l /dev/serial/by-path > > total 0 > > lrwxrwxrwx 1 root root 13 Jun 2 15:28 pci-0000:00:1d.0-usb-0:1.1:1.0-port0 -> ../../ttyUSB0 > > lrwxrwxrwx 1 root root 13 Jun 2 15:28 pci-0000:00:1d.0-usb-0:1.1:1.1-port0 -> ../../ttyUSB1 > > Ok, at least that matches what you found in schematics about this being > the ECI (and thus first) port. > > I just verified break signalling on the first port of my CP2105 using a > logic analyser and everything seems to work as expected. > > There's also no mention of any issue with break in the errata. > > Could you check which firmware revision you have by enabling debugging > and reconnecting the device? > > For example: > > echo func cp210x_get_fw_version +p > /sys/kernel/debug/dynamic_debug/control I couldn't get that to work (didn't try too hard), so I just stuck in a dev_info(): [ 4.253869] usb 2-1.2: new full-speed USB device number 3 using ehci-pci [ 4.342570] usb 2-1.2: New USB device found, idVendor=10c4, idProduct=ea70, bcdDevice= 1.00 [ 4.350939] usb 2-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=5 [ 4.358259] usb 2-1.2: Product: CP2105 Dual USB to UART Bridge Controller [ 4.365052] usb 2-1.2: Manufacturer: Silicon Labs [ 4.369765] usb 2-1.2: SerialNumber: 01070456 [ 4.374925] cp210x 2-1.2:1.0: cp210x converter detected [ 4.381086] cp210x 2-1.2:1.0: cp210x_get_fw_version - 1.18.1 [ 4.386915] usb 2-1.2: cp210x converter now attached to ttyUSB0 [ 4.393529] cp210x 2-1.2:1.1: cp210x converter detected [ 4.399835] cp210x 2-1.2:1.1: cp210x_get_fw_version - 1.18.1 [ 4.405657] usb 2-1.2: cp210x converter now attached to ttyUSB1 This is an embedded reference board, I guess there is some probability that this is just broken on this board, though I'm not quite sure how. Thanks for working on this. -corey