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=-1.1 required=3.0 tests=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 BC5F5C4332B for ; Tue, 24 Mar 2020 10:41:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8460D2070A for ; Tue, 24 Mar 2020 10:41:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585046506; bh=hKUMGa5wZ8KmkAlZ7gx4iZMSxMWyAZS3QMB9mOVvqaw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=WIrIhBLHWbsvWFRUaHYeMFXEsO+DQN5L1yg0nkePePTZhi1sqAmLsJXD3Ky70OBOo 1FXNwHzuM2vFiy+3bsz7ECtai57o6MAgqV4xydb4yV18DaL2xhv45vxZfwPUsb7BKv 6izgzniebDasodSXTTHhaU0ug+IW9K+EWtq4gWfU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727234AbgCXKlq (ORCPT ); Tue, 24 Mar 2020 06:41:46 -0400 Received: from mail-lf1-f65.google.com ([209.85.167.65]:45809 "EHLO mail-lf1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727084AbgCXKlp (ORCPT ); Tue, 24 Mar 2020 06:41:45 -0400 Received: by mail-lf1-f65.google.com with SMTP id v4so9072297lfo.12 for ; Tue, 24 Mar 2020 03:41:44 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=wqpD+wYNg1xqV0IVCC+VXA7Q+S6Q/yvjEmfajK9iKuk=; b=Cem/XEQlDDsBzNFXQd5uCkUU5iQvD2AGpqr8UlsUTuNueEryoJdmEsPNT0uN08JnO6 BwWuKGDPUXq5OheYq+0zoNvoQZUKkQNIerk7BrsqkmKLXh5/S6eYIPZXaO13vpQhPrlp /lk0X/KRSQfqW5LHp6q29CcOE/rAP4Yx7Q31brN7KZxriiAWBaWrGXfAL9w32xxc1dis AI632TmF+BJisLjZFSkCT5nrG+yDLq/uBIBaunjrMoWmCPWTe7wswH3/uRLxaRKFmPwF 8h/IDjI1QJM6gfsXFwLpIjMNTV3HdOCzf2MF8TC0IGyDufJXNWTgA2SCtM6O5JFHxf/K wBYg== X-Gm-Message-State: ANhLgQ0TZHqPhQWkq7Sa/vL8Hlc0SMT4KmLwQKN8b20MGuGsaDbr0gHL Laogfw8vTbChWixLUPUrd/8= X-Google-Smtp-Source: ADFU+vuDEXtu0owO8awz/KACW4rz8tufMrdDQy2MwmRYzbjVOVtiwz7P6DszG8SH8pOP7sntijutrA== X-Received: by 2002:a19:6416:: with SMTP id y22mr16074315lfb.60.1585046503326; Tue, 24 Mar 2020 03:41:43 -0700 (PDT) Received: from xi.terra (c-12aae455.07-184-6d6c6d4.bbcust.telenor.se. [85.228.170.18]) by smtp.gmail.com with ESMTPSA id l11sm9796879lfg.87.2020.03.24.03.41.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 24 Mar 2020 03:41:42 -0700 (PDT) Received: from johan by xi.terra with local (Exim 4.92.3) (envelope-from ) id 1jGgzz-0006bP-OA; Tue, 24 Mar 2020 11:41:31 +0100 Date: Tue, 24 Mar 2020 11:41:31 +0100 From: Johan Hovold To: Michael Hanselmann Cc: linux-usb@vger.kernel.org, Johan Hovold , Michael Dreher , Jonathan Olds Subject: Re: [PATCH 3/4] ch341: Limit prescaler on HL340 variant Message-ID: <20200324104131.GG5810@localhost> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Fri, Mar 06, 2020 at 07:00:44PM +0000, Michael Hanselmann wrote: > HL340 devices, a subset of all CH340 devices, do not work correctly when > the highest prescaler bit (0b100) is set. Limit these to the lower > prescaler values at the cost of timing precision. When we discussed this off list, you said that your device could handle the highest prescaler bit being set for some rates. You specifically confirmed that the 576000 and 921600 rates worked, while 110, 134 and 200 did not. Could you reconfirm which, if any, of the following rates work with the current driver? 1152000 921600 576000 200 134 110 Perhaps we can still continue supporting the higher rates, which are way off unless using the factor-2 prescaler. Johan