Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757660AbcDGUhf (ORCPT ); Thu, 7 Apr 2016 16:37:35 -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 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,449,1455004800"; d="scan'208";a="927815088" 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: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1806 Lines: 60 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; -- 2.8.0.rc3