From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751431AbbJ2HT0 (ORCPT ); Thu, 29 Oct 2015 03:19:26 -0400 Received: from mail-lb0-f174.google.com ([209.85.217.174]:34417 "EHLO mail-lb0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750828AbbJ2HTY (ORCPT ); Thu, 29 Oct 2015 03:19:24 -0400 Date: Thu, 29 Oct 2015 08:19:23 +0100 From: Johan Hovold To: Konstantin Shkolnyy Cc: johan@kernel.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 3/3] USB: serial: cp210x: Workaround cp2108 GET_LINE_CTL bug Message-ID: <20151029071923.GD32753@localhost> References: <1445982814-11638-1-git-send-email-konstantin.shkolnyy@gmail.com> <20151028085126.GA28572@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151028085126.GA28572@localhost> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 28, 2015 at 09:51:26AM +0100, Johan Hovold wrote: > On Tue, Oct 27, 2015 at 04:53:34PM -0500, Konstantin Shkolnyy wrote: > > cp2108 GET_LINE_CTL returns the 16-bit value with the 2 bytes swapped. > > However, SET_LINE_CTL functions properly. When the driver tries to modify > > the register, it reads it, modifies some bits and writes back. Because the > > read bytes were swapped, this often results in an invalid value to be > > written. In turn, this causes cp2108 respond with a stall. The stall > > sometimes doesn't clear properly and cp2108 starts responding to following > > valid commands also with stalls, effectively failing. > > > > Signed-off-by: Konstantin Shkolnyy > I gave the series a really quick test on an cp2102-device I had lying > around. I assume you verified the changes on some other older devices as > well? Did you test this series on the older device types as well? Thanks, Johan