From patchwork Mon May 18 16:47:20 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 6430621 Return-Path: X-Original-To: patchwork-linux-omap@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 54E54C0432 for ; Mon, 18 May 2015 16:47:29 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 32047205B9 for ; Mon, 18 May 2015 16:47:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E54FE20429 for ; Mon, 18 May 2015 16:47:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750911AbbERQrY (ORCPT ); Mon, 18 May 2015 12:47:24 -0400 Received: from www.linutronix.de ([62.245.132.108]:50045 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750771AbbERQrX (ORCPT ); Mon, 18 May 2015 12:47:23 -0400 Received: from bigeasy by Galois.linutronix.de with local (Exim 4.80) (envelope-from ) id 1YuOCG-0007q8-3r; Mon, 18 May 2015 18:47:20 +0200 Date: Mon, 18 May 2015 18:47:20 +0200 From: Sebastian Andrzej Siewior To: peter@hurleysoftware.com, linux-serial@vger.kernel.org Cc: linux-omap@vger.kernel.org, nsekhar@ti.com, tony@atomide.com, nm@ti.com Subject: [RFC PATCH] serial: 8250_omap: provide complete custom startup & shutdown callbacks Message-ID: <20150518164720.GA29261@linutronix.de> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_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 currently in-use port->startup and port->shutdown are "okay". The startup part for instance does the tiny omap extra part and invokes serial8250_do_startup() for the remaining pieces. The workflow in serial8250_do_startup() is okay except for the part where UART_RX is read without a check if there is something to read. I tried to workaround it in commit 0aa525d1 ("tty: serial: 8250_core: read only RX if there is something in the FIFO") but then reverted it later in commit ca8bb4aefb9 ("serial: 8250: Revert "tty: serial: 8250_core: read only RX if there is something in the FIFO""). This is the second attempt to get it to work on older OMAPs without breaking other chips this time :) Peter Hurley suggested to pull in the few needed lines from serial8250_do_startup() and drop everything else that is not required including makeing it simpler like using just request_irq() instead the chain handler like it is doing now. So lets try that. Signed-off-by: Sebastian Andrzej Siewior Tested-by: Tony Lindgren --- Peter is this what you had in mind? If so I will repost it without the RFC. And I think tony would like a stable + fixes tag for it. drivers/tty/serial/8250/8250_omap.c | 81 ++++++++++++++++++++++++++++++++----- 1 file changed, 72 insertions(+), 9 deletions(-) diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index 9289999cb7c6..7fd02a03c1ed 100644 --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -562,12 +562,36 @@ static irqreturn_t omap_wake_irq(int irq, void *dev_id) return IRQ_NONE; } +#ifdef CONFIG_SERIAL_8250_DMA +static int omap_8250_dma_handle_irq(struct uart_port *port); +#endif + +static irqreturn_t omap8250_irq(int irq, void *dev_id) +{ + struct uart_port *port = dev_id; + struct uart_8250_port *up = up_to_u8250p(port); + unsigned int iir; + int ret; + +#ifdef CONFIG_SERIAL_8250_DMA + if (up->dma) { + ret = omap_8250_dma_handle_irq(port); + return IRQ_RETVAL(ret); + } +#endif + + serial8250_rpm_get(up); + iir = serial_port_in(port, UART_IIR); + ret = serial8250_handle_irq(port, iir); + serial8250_rpm_put(up); + + return IRQ_RETVAL(ret); +} + static int omap_8250_startup(struct uart_port *port) { - struct uart_8250_port *up = - container_of(port, struct uart_8250_port, port); + struct uart_8250_port *up = up_to_u8250p(port); struct omap8250_priv *priv = port->private_data; - int ret; if (priv->wakeirq) { @@ -580,10 +604,31 @@ static int omap_8250_startup(struct uart_port *port) pm_runtime_get_sync(port->dev); - ret = serial8250_do_startup(port); - if (ret) + up->mcr = 0; + serial_out(up, UART_FCR, UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); + + serial_port_out(port, UART_LCR, UART_LCR_WLEN8); + + up->lsr_saved_flags = 0; + up->msr_saved_flags = 0; + + if (up->dma) { + ret = serial8250_request_dma(up); + if (ret) { + dev_warn_ratelimited(port->dev, + "failed to request DMA\n"); + up->dma = NULL; + } + } + + ret = request_irq(port->irq, omap8250_irq, IRQF_SHARED, + dev_name(port->dev), port); + if (ret < 0) goto err; + up->ier = UART_IER_RLSI | UART_IER_RDI; + serial_port_out(port, UART_IER, up->ier); + #ifdef CONFIG_PM up->capabilities |= UART_CAP_RPM; #endif @@ -610,8 +655,7 @@ static int omap_8250_startup(struct uart_port *port) static void omap_8250_shutdown(struct uart_port *port) { - struct uart_8250_port *up = - container_of(port, struct uart_8250_port, port); + struct uart_8250_port *up = up_to_u8250p(port); struct omap8250_priv *priv = port->private_data; flush_work(&priv->qos_work); @@ -621,11 +665,24 @@ static void omap_8250_shutdown(struct uart_port *port) pm_runtime_get_sync(port->dev); serial_out(up, UART_OMAP_WER, 0); - serial8250_do_shutdown(port); + + up->ier = 0; + serial_port_out(port, UART_IER, 0); + + if (up->dma) + serial8250_release_dma(up); + + /* + * Disable break condition and FIFOs + */ + if (up->lcr & UART_LCR_SBC) + serial_port_out(port, UART_LCR, up->lcr & ~UART_LCR_SBC); + serial_out(up, UART_FCR, UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); pm_runtime_mark_last_busy(port->dev); pm_runtime_put_autosuspend(port->dev); + free_irq(port->irq, port); if (priv->wakeirq) free_irq(priv->wakeirq, port); } @@ -974,6 +1031,12 @@ static inline int omap_8250_rx_dma(struct uart_8250_port *p, unsigned int iir) } #endif +static int omap8250_no_handle_irq(struct uart_port *port) +{ + WARN_ONCE(1, "This shouldn't be used\n"); + return 0; +} + static int omap8250_probe(struct platform_device *pdev) { struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); @@ -1075,6 +1138,7 @@ static int omap8250_probe(struct platform_device *pdev) pm_runtime_get_sync(&pdev->dev); omap_serial_fill_features_erratas(&up, priv); + up.port.handle_irq = omap8250_no_handle_irq; #ifdef CONFIG_SERIAL_8250_DMA if (pdev->dev.of_node) { /* @@ -1088,7 +1152,6 @@ static int omap8250_probe(struct platform_device *pdev) ret = of_property_count_strings(pdev->dev.of_node, "dma-names"); if (ret == 2) { up.dma = &priv->omap8250_dma; - up.port.handle_irq = omap_8250_dma_handle_irq; priv->omap8250_dma.fn = the_no_dma_filter_fn; priv->omap8250_dma.tx_dma = omap_8250_tx_dma; priv->omap8250_dma.rx_dma = omap_8250_rx_dma;