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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 0F685C43331 for ; Mon, 30 Mar 2020 14:52:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D06CD2072E for ; Mon, 30 Mar 2020 14:52:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728159AbgC3Owk (ORCPT ); Mon, 30 Mar 2020 10:52:40 -0400 Received: from mga12.intel.com ([192.55.52.136]:64494 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728091AbgC3Owk (ORCPT ); Mon, 30 Mar 2020 10:52:40 -0400 IronPort-SDR: MIRYyY5gaX862ksA0nrrp5J+dbtAUPZ5FOu0NRb0HzlBhHKMFR4129YBmmSgejwQTN9XlCFq4R JZ3fHnAkgupw== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Mar 2020 07:52:39 -0700 IronPort-SDR: rfW88gAjoLcRuxEMkeDyZmauk0DBi3xQ4Q1GXDFDjkXTWZvhWkbDmfca24k9dnZz35+i/xkTp/ EroFjNmfikxg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,324,1580803200"; d="scan'208";a="237374537" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by orsmga007.jf.intel.com with ESMTP; 30 Mar 2020 07:52:37 -0700 Received: from andy by smile with local (Exim 4.93) (envelope-from ) id 1jIvmJ-00EEWj-7l; Mon, 30 Mar 2020 17:52:39 +0300 Date: Mon, 30 Mar 2020 17:52:39 +0300 From: Andy Shevchenko To: Heiko Stuebner Cc: gregkh@linuxfoundation.org, jslaby@suse.com, matwey.kornilov@gmail.com, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, lukas@wunner.de, christoph.muellner@theobroma-systems.com, giulio.benetti@micronovasrl.com, Heiko Stuebner Subject: Re: [PATCH v2 4/7] serial: 8250: Handle implementations not having TEMT interrupt using em485 Message-ID: <20200330145239.GV1922688@smile.fi.intel.com> References: <20200325231422.1502366-1-heiko@sntech.de> <20200325231422.1502366-5-heiko@sntech.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200325231422.1502366-5-heiko@sntech.de> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Sender: linux-serial-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org On Thu, Mar 26, 2020 at 12:14:19AM +0100, Heiko Stuebner wrote: > From: Giulio Benetti > > Some 8250 ports have a TEMT interrupt but it's not a part of the 8250 > standard, instead only available on some implementations. > > The current em485 implementation does not work on ports without it. > The only chance to make it work is to loop-read on LSR register. > > So add UART_CAP_TEMT to mark 8250 uarts having this interrupt, > update all current em485 users with that capability and make > the stop_tx function loop-read on uarts not having it. > + if (p->capabilities & UART_CAP_TEMT) { > + if ((lsr & BOTH_EMPTY) != BOTH_EMPTY) > + return; > + } else { > + int lsr; > + > + if (readx_poll_timeout(__get_lsr, p, lsr, > + (lsr & BOTH_EMPTY) == BOTH_EMPTY, > + 0, 10000) < 0) ret = readx_poll_timeout(...); if (ret) ... will look better. > + pr_warn("%s: timeout waiting for fifos to empty\n", > + p->port.name); > + } -- With Best Regards, Andy Shevchenko