From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754117AbaG2TB3 (ORCPT ); Tue, 29 Jul 2014 15:01:29 -0400 Received: from www.linutronix.de ([62.245.132.108]:50358 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751439AbaG2TAS (ORCPT ); Tue, 29 Jul 2014 15:00:18 -0400 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, Sebastian Andrzej Siewior , Heikki Krogerus Subject: [RFC PATCH 4/7] serial: 8250_dma: enqueue RX dma again on completion. Date: Tue, 29 Jul 2014 20:59:01 +0200 Message-Id: <1406660344-25307-5-git-send-email-bigeasy@linutronix.de> X-Mailer: git-send-email 2.0.1 In-Reply-To: <1406660344-25307-1-git-send-email-bigeasy@linutronix.de> References: <1406660344-25307-1-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-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 requeues RX-DMA request on completion but not if it was canceled due to the RX-timeout. Cc: Heikki Krogerus Signed-off-by: Sebastian Andrzej Siewior --- drivers/tty/serial/8250/8250_core.c | 3 +++ drivers/tty/serial/8250/8250_dma.c | 12 +++++++++--- 2 files changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index 7a33c30..098ff02 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -1556,6 +1556,9 @@ 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 == -ETIMEDOUT && port->type == PORT_OMAP_16750) + serial8250_rx_dma(up, 0); } serial8250_modem_status(up); if (!up->dma && (status & UART_LSR_THRE)) diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c index f9ef69f..acb0a87 100644 --- a/drivers/tty/serial/8250/8250_dma.c +++ b/drivers/tty/serial/8250/8250_dma.c @@ -49,9 +49,8 @@ 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 timeout) { - 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; @@ -67,10 +66,17 @@ static void __dma_rx_complete(void *param) tty_insert_flip_string(tty_port, dma->rx_buf, count); p->port.icount.rx += count; + if (!timeout && p->port.type == PORT_OMAP_16750) + 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; @@ -126,7 +132,7 @@ 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: -- 2.0.1