From patchwork Wed Sep 10 19:30:03 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 4880291 Return-Path: X-Original-To: patchwork-linux-omap@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 8444C9F32E for ; Wed, 10 Sep 2014 19:34:00 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id ACA02201DD for ; Wed, 10 Sep 2014 19:33:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C1FD2201C8 for ; Wed, 10 Sep 2014 19:33:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753546AbaIJTd1 (ORCPT ); Wed, 10 Sep 2014 15:33:27 -0400 Received: from www.linutronix.de ([62.245.132.108]:35370 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751717AbaIJTaV (ORCPT ); Wed, 10 Sep 2014 15:30:21 -0400 Received: from localhost ([127.0.0.1] helo=bazinga.breakpoint.cc) by Galois.linutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1XRnas-0001bs-Qd; Wed, 10 Sep 2014 21:30:18 +0200 From: Sebastian Andrzej Siewior To: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, tony@atomide.com, balbi@ti.com, gregkh@linuxfoundation.org, Sebastian Andrzej Siewior Subject: [PATCH 08/16] tty: serial: 8250_dma: enqueue RX dma again on completion. Date: Wed, 10 Sep 2014 21:30:03 +0200 Message-Id: <1410377411-26656-9-git-send-email-bigeasy@linutronix.de> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1410377411-26656-1-git-send-email-bigeasy@linutronix.de> References: <1410377411-26656-1-git-send-email-bigeasy@linutronix.de> X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1, SHORTCIRCUIT=-0.0001 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Spam-Status: No, score=-9.4 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 The omap needs a DMA request pending right away. If it is enqueued once the bytes are in the FIFO then nothing will happen and the FIFO will be later purged via RX-timeout interrupt. This patch enqueues RX-DMA request on completion but not if it was aborted on error. The first enqueue will happen in the driver in startup. Reviewed-by: Tony Lindgren Tested-by: Tony Lindgren Signed-off-by: Sebastian Andrzej Siewior --- drivers/tty/serial/8250/8250.h | 3 ++- drivers/tty/serial/8250/8250_core.c | 3 +++ drivers/tty/serial/8250/8250_dma.c | 12 +++++++++--- 3 files changed, 14 insertions(+), 4 deletions(-) diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h index a63d198f8d03..fbed1636e9c4 100644 --- a/drivers/tty/serial/8250/8250.h +++ b/drivers/tty/serial/8250/8250.h @@ -80,7 +80,8 @@ struct serial8250_config { #define UART_BUG_NOMSR (1 << 2) /* UART has buggy MSR status bits (Au1x00) */ #define UART_BUG_THRE (1 << 3) /* UART has buggy THRE reassertion */ #define UART_BUG_PARITY (1 << 4) /* UART mishandles parity if FIFO enabled */ - +#define UART_BUG_DMA_RX (1 << 5) /* UART needs DMA RX req before there is + data in FIFO */ #define PROBE_RSA (1 << 0) #define PROBE_ANY (~0) diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index 9f961ea82564..39b1c7318f17 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -1592,6 +1592,9 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir) if (!up->dma || dma_err) status = serial8250_rx_chars(up, status); + + if (dma_err && up->bugs & UART_BUG_DMA_RX) + serial8250_rx_dma(up, 0); } serial8250_modem_status(up); if ((!up->dma || (up->dma && up->dma->tx_err)) && diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c index 69e54abb6e71..3674900a1f14 100644 --- a/drivers/tty/serial/8250/8250_dma.c +++ b/drivers/tty/serial/8250/8250_dma.c @@ -50,9 +50,8 @@ static void __dma_tx_complete(void *param) spin_unlock_irqrestore(&p->port.lock, flags); } -static void __dma_rx_complete(void *param) +static void __dma_rx_do_complete(struct uart_8250_port *p, bool error) { - struct uart_8250_port *p = param; struct uart_8250_dma *dma = p->dma; struct tty_port *tty_port = &p->port.state->port; struct dma_tx_state state; @@ -68,10 +67,17 @@ static void __dma_rx_complete(void *param) tty_insert_flip_string(tty_port, dma->rx_buf, count); p->port.icount.rx += count; + if (!error && p->bugs & UART_BUG_DMA_RX) + serial8250_rx_dma(p, 0); tty_flip_buffer_push(tty_port); } +static void __dma_rx_complete(void *param) +{ + __dma_rx_do_complete(param, false); +} + int serial8250_tx_dma(struct uart_8250_port *p) { struct uart_8250_dma *dma = p->dma; @@ -139,7 +145,7 @@ int serial8250_rx_dma(struct uart_8250_port *p, unsigned int iir) */ if (dma_status == DMA_IN_PROGRESS) { dmaengine_pause(dma->rxchan); - __dma_rx_complete(p); + __dma_rx_do_complete(p, true); } return -ETIMEDOUT; default: