From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1752694AbcIIO2l (ORCPT <rfc822;w@1wt.eu>);
        Fri, 9 Sep 2016 10:28:41 -0400
Received: from mga03.intel.com ([134.134.136.65]:10657 "EHLO mga03.intel.com"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S1750841AbcIIO2i (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Fri, 9 Sep 2016 10:28:38 -0400
X-ExtLoop1: 1
X-IronPort-AV: E=Sophos;i="5.30,305,1470726000"; 
   d="scan'208";a="758829904"
Message-ID: <1473431313.11323.159.camel@linux.intel.com>
Subject: Re: [RFC RESEND] serial: 8250: fix regression in 8250 uart driver
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Dinh Nguyen <dinguyen@kernel.org>,
        Thorsten Leemhuis <regressions@leemhuis.info>
Cc: heikki.krogerus@linux.intel.com, peter@hurleysoftware.com,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org
Date: Fri, 09 Sep 2016 17:28:33 +0300
In-Reply-To: <af26be97-ff08-8a07-b9c7-fc674056507e@kernel.org>
References: <575F7325.3030907@kernel.org>
         <1465897220.30123.26.camel@linux.intel.com>
         <cca9fb6eca58d8a29e3070e3f34fa40f.squirrel@emailmg.ipower.com>
         <1465920046.30123.83.camel@linux.intel.com>
         <dbaa0abe-06ab-57ee-4ba3-4e4717af4a62@leemhuis.info>
         <1471432466.4887.134.camel@linux.intel.com>
         <abf9f9cb-c14c-7efb-8d1c-ed89a6a979a3@kernel.org>
         <1473268564.11323.91.camel@linux.intel.com>
         <af26be97-ff08-8a07-b9c7-fc674056507e@kernel.org>
Organization: Intel Finland Oy
Content-Type: text/plain; charset="UTF-8"
X-Mailer: Evolution 3.20.5-1 
Mime-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Fri, 2016-09-09 at 08:57 -0500, Dinh Nguyen wrote:
> 
> On 09/07/2016 12:16 PM, Andy Shevchenko wrote:
> > 
> > On Tue, 2016-08-23 at 08:53 -0500, Dinh Nguyen wrote:
> > > 
> > > Hi Andy,
> > > 
> > > On 08/17/2016 06:14 AM, Andy Shevchenko wrote:
> > > > 
> > > > 
> > > > 
> > > > I sent a v2 of the series for internal review, same you may
> > > > found on
> > > > [1]. If Heikki is okay to that I'll send it here.
> > > > 
> > > > [1] https://bitbucket.org/andy-shev/linux/branch/topic%2Fdw%2Fqr
> > > > k
> > > > 
> > > 
> > > I tested this branch on SoCFPGA hardware and encountered this
> > > error[1].
> > > Doing a bisect led me to this commit[2].
> > 
> > Forgot to add you to Cc list, there is new version there.
> > 
> 
> I'm no longer getting the previous error, but I am still seeing this:
> 
> [    6.025749] ttyS0 - failed to request DMA

As Peter told you your DMA engine doesn't provide everything UART driver
needs to establish such transfers.

My patchset does not prevent that check. It might be fixed, but I don't
know yet the proper way. Any suggestions you have, please, comment at
the series [1] directly.

[1] http://www.spinics.net/lists/linux-serial/msg23608.html

-- 
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy