From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Wed, 01 Mar 2017 19:50:39 +0100 (CET) Received: from mga01.intel.com ([192.55.52.88]:39159 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S23992214AbdCASu1CHlB5 (ORCPT ); Wed, 1 Mar 2017 19:50:27 +0100 Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 01 Mar 2017 10:50:24 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.35,226,1484035200"; d="scan'208";a="1103679445" Received: from smile.fi.intel.com (HELO smile) ([10.237.72.86]) by orsmga001.jf.intel.com with ESMTP; 01 Mar 2017 10:50:20 -0800 Message-ID: <1488394220.20145.68.camel@linux.intel.com> Subject: Re: [PATCH v2 1/1] serial: 8250_dw: Allow hardware flow control to be used From: Andy Shevchenko To: James Hogan , Jason Uy Cc: Greg Kroah-Hartman , Jiri Slaby , Kefeng Wang , Noam Camus , Heikki Krogerus , Wang Hongcheng , linux-serial@vger.kernel.org, LKML , bcm-kernel-feedback-list@broadcom.com, Linux MIPS Mailing List , David Daney Date: Wed, 01 Mar 2017 20:50:20 +0200 In-Reply-To: References: <1484164100-9805-1-git-send-email-jason.uy@broadcom.com> <1484164100-9805-2-git-send-email-jason.uy@broadcom.com> Organization: Intel Finland Oy Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.5-1 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 56950 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: andriy.shevchenko@linux.intel.com Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips On Wed, 2017-03-01 at 18:02 +0000, James Hogan wrote: > On 11 January 2017 at 19:48, Jason Uy wrote: > > In the most common use case, the Synopsys DW UART driver does not > > set the set_termios callback function.  This prevents UPSTAT_AUTOCTS > > from being set when the UART flag CRTSCTS is set.  As a result, the > > driver will use software flow control as opposed to hardware flow > > control. > > > > To fix the problem, the set_termios callback function is set to the > > DW specific function.  The logic to set UPSTAT_AUTOCTS is moved so > > that any clock error will not affect setting the hardware flow > > control. > Bisection shows that this patch, commit > 6a171b29937984a5e0bf29d6577b055998f03edb, has broken boot of the > Cavium Octeon III based UTM-8 board (MIPS architecture). > > I now get the following warning: > [] uart_get_baud_rate+0xfc/0x1f0 > [] serial8250_do_set_termios+0xb0/0x440 > [] uart_set_options+0xe8/0x190 > [] serial8250_console_setup+0x84/0x158 > [] univ8250_console_setup+0x54/0x70 > [] register_console+0x1c8/0x418 > [] uart_add_one_port+0x434/0x4b0 > [] serial8250_register_8250_port+0x2d8/0x440 > [] dw8250_probe+0x388/0x5e8 > Then it hangs and the watchdog restarts the machine. > > Any ideas? 1. Does it use clock on that platform? 2. Check if termios is not NULL there. -- Andy Shevchenko Intel Finland Oy