From patchwork Thu Apr 7 20:37:07 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Shevchenko X-Patchwork-Id: 8776991 Return-Path: X-Original-To: patchwork-dmaengine@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id ABD149F36E for ; Thu, 7 Apr 2016 20:38:37 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id CF07620222 for ; Thu, 7 Apr 2016 20:38:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BC4B12024F for ; Thu, 7 Apr 2016 20:38:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757598AbcDGUha (ORCPT ); Thu, 7 Apr 2016 16:37:30 -0400 Received: from mga01.intel.com ([192.55.52.88]:60174 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755544AbcDGUhZ (ORCPT ); Thu, 7 Apr 2016 16:37:25 -0400 Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga101.fm.intel.com with ESMTP; 07 Apr 2016 13:37:21 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,449,1455004800"; d="scan'208";a="927815088" Received: from black.fi.intel.com ([10.237.72.93]) by orsmga001.jf.intel.com with ESMTP; 07 Apr 2016 13:37:18 -0700 Received: by black.fi.intel.com (Postfix, from userid 1003) id 7B81EE0; Thu, 7 Apr 2016 23:37:14 +0300 (EEST) From: Andy Shevchenko To: Vinod Koul , linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org, Greg Kroah-Hartman , ismo.puustinen@intel.com, Heikki Krogerus , linux-serial@vger.kernel.org Cc: Andy Shevchenko Subject: [PATCH v1 06/12] serial: 8250_dma: stop ongoing RX DMA on exception Date: Thu, 7 Apr 2016 23:37:07 +0300 Message-Id: <1460061433-63750-7-git-send-email-andriy.shevchenko@linux.intel.com> X-Mailer: git-send-email 2.8.0.rc3 In-Reply-To: <1460061433-63750-1-git-send-email-andriy.shevchenko@linux.intel.com> References: <1460061433-63750-1-git-send-email-andriy.shevchenko@linux.intel.com> Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org X-Spam-Status: No, score=-7.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If we get an exeption interrupt. i.e. UART_IIR_RLSI, stop any ongoing RX DMA transfer otherwise it might generates more spurious interrupts and make port unavailable anymore. As has been seen on Intel Broxton system: ... [ 168.526281] serial8250: too much work for irq5 [ 168.535908] serial8250: too much work for irq5 [ 173.449464] serial8250_interrupt: 4439 callbacks suppressed [ 173.455694] serial8250: too much work for irq5 ... Signed-off-by: Andy Shevchenko --- drivers/tty/serial/8250/8250_dma.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c index 9d80bb1..b134bec 100644 --- a/drivers/tty/serial/8250/8250_dma.c +++ b/drivers/tty/serial/8250/8250_dma.c @@ -110,6 +110,16 @@ err: return ret; } +static void __dma_rx_stop(struct uart_8250_port *p, struct uart_8250_dma *dma) +{ + if (!dma->rx_running) + return; + + dmaengine_pause(dma->rxchan); + __dma_rx_complete(p); + dmaengine_terminate_async(dma->rxchan); +} + int serial8250_rx_dma(struct uart_8250_port *p, unsigned int iir) { struct uart_8250_dma *dma = p->dma; @@ -118,17 +128,14 @@ int serial8250_rx_dma(struct uart_8250_port *p, unsigned int iir) switch (iir & 0x3f) { case UART_IIR_RLSI: /* 8250_core handles errors and break interrupts */ + __dma_rx_stop(p, dma); return -EIO; case UART_IIR_RX_TIMEOUT: /* * If RCVR FIFO trigger level was not reached, complete the * transfer and let 8250_core copy the remaining data. */ - if (dma->rx_running) { - dmaengine_pause(dma->rxchan); - __dma_rx_complete(p); - dmaengine_terminate_async(dma->rxchan); - } + __dma_rx_stop(p, dma); return -ETIMEDOUT; default: break;