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 X-Spam-Level: X-Spam-Status: No, score=-6.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 110C0C47094 for ; Mon, 7 Jun 2021 16:53:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E5F346100B for ; Mon, 7 Jun 2021 16:53:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231410AbhFGQy6 (ORCPT ); Mon, 7 Jun 2021 12:54:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:45056 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230446AbhFGQy5 (ORCPT ); Mon, 7 Jun 2021 12:54:57 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 51E3160FDA; Mon, 7 Jun 2021 16:53:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1623084786; bh=/tfrK9SqrQkiyu3G5dlDMR6ncPkcSVXzOtse53jthQc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=pmB9YcbGuCg0rJhjltEoNfL7o/NFozO5di3+ex1teSStlbQGoQWltQPu8epEVmZp8 3kkz5vhhl7pUwGZaM8cYMSwsgq+JFJLAoNJh5mBGFb+l/oM6FGf9kDYM3FjysGGjXE dWS0K29O53nxix87xprF/26lYeDOR1HuILAIC4mM3mGtrtBYw6dFGF1V+ZJNNb4xKz U9zwC+Y7+Gwn4gfw9AB24aG3bYfyrDnmayf3LI5OAy415qmT8xYI5cOL3DA8PZ464b 4tE/F7q8w0NFeCHlM+QPnwfk7xGKNUsGdC9zHw2FDuvu2H8ARlRuairITlx7AjEYL/ Xi4S45p7EXteQ== Received: from johan by xi.lan with local (Exim 4.94.2) (envelope-from ) id 1lqIUl-0003Cq-N0; Mon, 07 Jun 2021 18:53:00 +0200 Date: Mon, 7 Jun 2021 18:52:59 +0200 From: Johan Hovold To: David Frey Cc: Alex =?utf-8?B?VmlsbGFjw61z?= Lasso , linux-usb@vger.kernel.org, Pho Tran , Tung Pham , Hung.Nguyen@silabs.com Subject: Re: cp210x module broken in 5.12.5 and 5.12.6, works in 5.11.21 (with bisection) Message-ID: References: <2881bd97-f790-c4d6-aed6-de9ab8cd1a9e@palosanto.com> <60705932-860a-701c-1019-16f9e16c39dd@palosanto.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Mon, Jun 07, 2021 at 09:44:59AM -0700, David Frey wrote: > On Sat, Jun 5, 2021 at 3:13 AM Johan Hovold wrote: > > > > I found an errata for A01 on here, but no mention if this particular > > bug: > > > > https://www.silabs.com/documents/public/pcns/190315471-CP2102N-Product-Revision-with-Datasheet-and-Errata-Update.pdf > > I believe this document has some more errata details: > https://www.silabs.com/documents/public/errata/cp2102n-errata.pdf' Thanks for the link. This seems to confirm that this is a known issue with A01 that was fixed in A02: 3.6 CP2102N_E104 – IO Exception in .NET Applications when Manually Controlling RTS The CP2102N uses the incorrect byte of the SERIAL_HANDFLOW structure (https://msdn.microsoft.com/en-us/library/windows/hard- ware/jj680685(v=vs.85).aspx) to control the RTS signal. Instead of looking at the first byte of FlowReplace, the device is reading the first byte of the XonLimit and interpreting that as the first byte of FlowReplace. Applications written in .NET set the Xon/Xoff limits to 160, equal to 0xA0, which the CP2102N interprets as hardware flow control, and so it returns an error when manually setting RTS. Now we just need to figure out how to determine the firmware revision. Johan