From patchwork Fri Jun 17 10:05:47 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Ferre X-Patchwork-Id: 9183203 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 64AA660776 for ; Fri, 17 Jun 2016 10:07:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 54EA828385 for ; Fri, 17 Jun 2016 10:07:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 49A1C2839C; Fri, 17 Jun 2016 10:07:35 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id D62C328385 for ; Fri, 17 Jun 2016 10:07:34 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1bDqfQ-0000K7-Pd; Fri, 17 Jun 2016 10:06:24 +0000 Received: from eusmtp01.atmel.com ([212.144.249.243]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1bDqfN-0000AM-T7 for linux-arm-kernel@lists.infradead.org; Fri, 17 Jun 2016 10:06:22 +0000 Received: from tenerife.corp.atmel.com (10.161.101.13) by eusmtp01.atmel.com (10.161.101.31) with Microsoft SMTP Server id 14.3.235.1; Fri, 17 Jun 2016 12:05:54 +0200 From: Nicolas Ferre To: Greg Kroah-Hartman , , Alexandre Belloni , Subject: [RESEND PATCH 2/4] tty/serial: atmel: split tx and rx paths Date: Fri, 17 Jun 2016 12:05:47 +0200 Message-ID: X-Mailer: git-send-email 2.9.0 In-Reply-To: References: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160617_030622_262464_E6425AF1 X-CRM114-Status: GOOD ( 11.71 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Boris BREZILLON , Ludovic Desroches , Nicolas Ferre , linux-kernel@vger.kernel.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Split TX and RX paths to not schedule RX tasklet on TX events and vice versa. Signed-off-by: Nicolas Ferre Signed-off-by: Ludovic Desroches --- drivers/tty/serial/atmel_serial.c | 53 +++++++++++++++++++++++++-------------- 1 file changed, 34 insertions(+), 19 deletions(-) diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index 8854ac6f383d..6c1ec7d0d497 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -145,7 +145,8 @@ struct atmel_uart_port { dma_cookie_t cookie_rx; struct scatterlist sg_tx; struct scatterlist sg_rx; - struct tasklet_struct tasklet; + struct tasklet_struct tasklet_rx; + struct tasklet_struct tasklet_tx; unsigned int irq_status_prev; unsigned int tx_len; @@ -708,7 +709,7 @@ static void atmel_rx_chars(struct uart_port *port) status = atmel_uart_readl(port, ATMEL_US_CSR); } - tasklet_schedule(&atmel_port->tasklet); + tasklet_schedule(&atmel_port->tasklet_rx); } /* @@ -779,7 +780,7 @@ static void atmel_complete_tx_dma(void *arg) * remaining data from the beginning of xmit->buf to xmit->head. */ if (!uart_circ_empty(xmit)) - tasklet_schedule(&atmel_port->tasklet); + tasklet_schedule(&atmel_port->tasklet_tx); spin_unlock_irqrestore(&port->lock, flags); } @@ -964,7 +965,7 @@ static void atmel_complete_rx_dma(void *arg) struct uart_port *port = arg; struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); - tasklet_schedule(&atmel_port->tasklet); + tasklet_schedule(&atmel_port->tasklet_rx); } static void atmel_release_rx_dma(struct uart_port *port) @@ -1004,7 +1005,7 @@ static void atmel_rx_from_dma(struct uart_port *port) if (dmastat == DMA_ERROR) { dev_dbg(port->dev, "Get residue error, restart tasklet\n"); atmel_uart_writel(port, ATMEL_US_IER, ATMEL_US_TIMEOUT); - tasklet_schedule(&atmel_port->tasklet); + tasklet_schedule(&atmel_port->tasklet_rx); return; } @@ -1158,7 +1159,7 @@ static void atmel_uart_timer_callback(unsigned long data) struct uart_port *port = (void *)data; struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); - tasklet_schedule(&atmel_port->tasklet); + tasklet_schedule(&atmel_port->tasklet_rx); mod_timer(&atmel_port->uart_timer, jiffies + uart_poll_timeout(port)); } @@ -1181,7 +1182,7 @@ atmel_handle_receive(struct uart_port *port, unsigned int pending) if (pending & (ATMEL_US_ENDRX | ATMEL_US_TIMEOUT)) { atmel_uart_writel(port, ATMEL_US_IDR, (ATMEL_US_ENDRX | ATMEL_US_TIMEOUT)); - tasklet_schedule(&atmel_port->tasklet); + tasklet_schedule(&atmel_port->tasklet_rx); } if (pending & (ATMEL_US_RXBRK | ATMEL_US_OVRE | @@ -1193,7 +1194,7 @@ atmel_handle_receive(struct uart_port *port, unsigned int pending) if (pending & ATMEL_US_TIMEOUT) { atmel_uart_writel(port, ATMEL_US_IDR, ATMEL_US_TIMEOUT); - tasklet_schedule(&atmel_port->tasklet); + tasklet_schedule(&atmel_port->tasklet_rx); } } @@ -1223,7 +1224,7 @@ atmel_handle_transmit(struct uart_port *port, unsigned int pending) /* Either PDC or interrupt transmission */ atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask); - tasklet_schedule(&atmel_port->tasklet); + tasklet_schedule(&atmel_port->tasklet_tx); } } @@ -1582,18 +1583,25 @@ static int atmel_prepare_rx_pdc(struct uart_port *port) /* * tasklet handling tty stuff outside the interrupt handler. */ -static void atmel_tasklet_func(unsigned long data) +static void atmel_tasklet_rx_func(unsigned long data) { struct uart_port *port = (struct uart_port *)data; struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); /* The interrupt handler does not take the lock */ spin_lock(&port->lock); - - atmel_port->schedule_tx(port); - atmel_port->schedule_rx(port); + spin_unlock(&port->lock); +} +static void atmel_tasklet_tx_func(unsigned long data) +{ + struct uart_port *port = (struct uart_port *)data; + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); + + /* The interrupt handler does not take the lock */ + spin_lock(&port->lock); + atmel_port->schedule_tx(port); spin_unlock(&port->lock); } @@ -1777,7 +1785,8 @@ static int atmel_startup(struct uart_port *port) return retval; } - tasklet_enable(&atmel_port->tasklet); + tasklet_enable(&atmel_port->tasklet_rx); + tasklet_enable(&atmel_port->tasklet_tx); /* * Initialize DMA (if necessary) @@ -1906,8 +1915,10 @@ static void atmel_shutdown(struct uart_port *port) * Clear out any scheduled tasklets before * we destroy the buffers */ - tasklet_disable(&atmel_port->tasklet); - tasklet_kill(&atmel_port->tasklet); + tasklet_disable(&atmel_port->tasklet_rx); + tasklet_disable(&atmel_port->tasklet_tx); + tasklet_kill(&atmel_port->tasklet_rx); + tasklet_kill(&atmel_port->tasklet_tx); /* * Ensure everything is stopped and @@ -2302,9 +2313,12 @@ static int atmel_init_port(struct atmel_uart_port *atmel_port, port->irq = pdev->resource[1].start; port->rs485_config = atmel_config_rs485; - tasklet_init(&atmel_port->tasklet, atmel_tasklet_func, + tasklet_init(&atmel_port->tasklet_rx, atmel_tasklet_rx_func, + (unsigned long)port); + tasklet_init(&atmel_port->tasklet_tx, atmel_tasklet_tx_func, (unsigned long)port); - tasklet_disable(&atmel_port->tasklet); + tasklet_disable(&atmel_port->tasklet_rx); + tasklet_disable(&atmel_port->tasklet_tx); memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring)); @@ -2786,7 +2800,8 @@ static int atmel_serial_remove(struct platform_device *pdev) struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); int ret = 0; - tasklet_kill(&atmel_port->tasklet); + tasklet_kill(&atmel_port->tasklet_rx); + tasklet_kill(&atmel_port->tasklet_tx); device_init_wakeup(&pdev->dev, 0);