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 BBD9EC7EE2A for ; Mon, 5 Jun 2023 07:16:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231263AbjFEHQM (ORCPT ); Mon, 5 Jun 2023 03:16:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48526 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230145AbjFEHQI (ORCPT ); Mon, 5 Jun 2023 03:16:08 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 555021BD; Mon, 5 Jun 2023 00:15:43 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 211BA60F19; Mon, 5 Jun 2023 07:15:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7BC8CC433EF; Mon, 5 Jun 2023 07:15:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1685949312; bh=RV1uSWYECRF6po/E+w6yWpCHTfpG9zLcmT+80L61Dp8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HtOtJiV5bbausUrO3yqE5B5ePbLaipOSV60pQ7DMAmGts71BW2BZnaNt2GDJZ3vMg JqD39VkYSSH5Qypp/+nEjZxdf9IfW2aTFp/4L89ESCYjz0gw34ydjp6nSoZpNukv+s Kx1gx1dqWbHW24bYOjS0t8JF/9eCcwbNUQpC0PP8DGp90nH9J6AaDnBIppPeM6H30C koIYRScxM9U+YmgAFTMLfGpXGvij9UG0WZLohVN+612rV5TeM2IWGhgmj+krM52YDX 8Kt9rrZSrzqA30kmd08ZN97pobyijFWBHHfzBgzsm3RdLdYGd1zemVjV77+aKtzQwL 542Nw1ZqwNkkQ== Received: from johan by xi.lan with local (Exim 4.94.2) (envelope-from ) id 1q64R6-00077O-OC; Mon, 05 Jun 2023 09:15:29 +0200 Date: Mon, 5 Jun 2023 09:15:28 +0200 From: Johan Hovold To: Corey Minyard Cc: Craig Shelley , Linux Kernel , linux-usb@vger.kernel.org Subject: Re: Break doesn't work on a CP2105 Message-ID: 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 03:11:43PM -0500, Corey Minyard wrote: > On Sun, Jun 04, 2023 at 02:17:16PM +0200, Johan Hovold wrote: > > 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? > [ 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 So we have the same firmware revision. > 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. Is the port accessible somehow so that you could hook up a scope or logic analyser? Or is that what you did already when you mentioned seeing garbage sent after 2.5 seconds? That last bit seems to match the behaviour I see with the second, SCI port, where the last character sent is resent when trying to signal a break. Johan