From patchwork Thu Mar 4 21:38:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hector Martin X-Patchwork-Id: 393759 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CEC28C43381 for ; Thu, 4 Mar 2021 21:43:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9835A65010 for ; Thu, 4 Mar 2021 21:43:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240817AbhCDVnC (ORCPT ); Thu, 4 Mar 2021 16:43:02 -0500 Received: from marcansoft.com ([212.63.210.85]:34610 "EHLO mail.marcansoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240690AbhCDVmk (ORCPT ); Thu, 4 Mar 2021 16:42:40 -0500 Received: from [127.0.0.1] (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: hector@marcansoft.com) by mail.marcansoft.com (Postfix) with ESMTPSA id 0C02E426FC; Thu, 4 Mar 2021 21:41:49 +0000 (UTC) From: Hector Martin To: linux-arm-kernel@lists.infradead.org Cc: Hector Martin , Marc Zyngier , Rob Herring , Arnd Bergmann , Olof Johansson , Krzysztof Kozlowski , Mark Kettenis , Tony Lindgren , Mohamed Mediouni , Stan Skowronek , Alexander Graf , Will Deacon , Linus Walleij , Mark Rutland , Andy Shevchenko , Greg Kroah-Hartman , Jonathan Corbet , Catalin Marinas , Christoph Hellwig , "David S. Miller" , devicetree@vger.kernel.org, linux-serial@vger.kernel.org, linux-doc@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFT PATCH v3 21/27] tty: serial: samsung_tty: IRQ rework Date: Fri, 5 Mar 2021 06:38:56 +0900 Message-Id: <20210304213902.83903-22-marcan@marcan.st> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210304213902.83903-1-marcan@marcan.st> References: <20210304213902.83903-1-marcan@marcan.st> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org * Split out s3c24xx_serial_tx_chars from s3c24xx_serial_tx_irq, where only the latter acquires the port lock. This will be necessary on platforms which have edge-triggered IRQs, as we need to call s3c24xx_serial_tx_chars to kick off transmission from outside IRQ context, with the port lock held. * Rename s3c24xx_serial_rx_chars to s3c24xx_serial_rx_irq for consistency with the above. All it does now is call two other functions anyway. Signed-off-by: Hector Martin Reviewed-by: Krzysztof Kozlowski Tested-by: Krzysztof Kozlowski --- drivers/tty/serial/samsung_tty.c | 34 +++++++++++++++++++------------- 1 file changed, 20 insertions(+), 14 deletions(-) diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c index 39b2eb165bdc..7106eb238d8c 100644 --- a/drivers/tty/serial/samsung_tty.c +++ b/drivers/tty/serial/samsung_tty.c @@ -827,7 +827,7 @@ static irqreturn_t s3c24xx_serial_rx_chars_pio(void *dev_id) return IRQ_HANDLED; } -static irqreturn_t s3c24xx_serial_rx_chars(int irq, void *dev_id) +static irqreturn_t s3c24xx_serial_rx_irq(int irq, void *dev_id) { struct s3c24xx_uart_port *ourport = dev_id; @@ -836,16 +836,12 @@ static irqreturn_t s3c24xx_serial_rx_chars(int irq, void *dev_id) return s3c24xx_serial_rx_chars_pio(dev_id); } -static irqreturn_t s3c24xx_serial_tx_chars(int irq, void *id) +static void s3c24xx_serial_tx_chars(struct s3c24xx_uart_port *ourport) { - struct s3c24xx_uart_port *ourport = id; struct uart_port *port = &ourport->port; struct circ_buf *xmit = &port->state->xmit; - unsigned long flags; int count, dma_count = 0; - spin_lock_irqsave(&port->lock, flags); - count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); if (ourport->dma && ourport->dma->tx_chan && @@ -862,7 +858,7 @@ static irqreturn_t s3c24xx_serial_tx_chars(int irq, void *id) wr_reg(port, S3C2410_UTXH, port->x_char); port->icount.tx++; port->x_char = 0; - goto out; + return; } /* if there isn't anything more to transmit, or the uart is now @@ -871,7 +867,7 @@ static irqreturn_t s3c24xx_serial_tx_chars(int irq, void *id) if (uart_circ_empty(xmit) || uart_tx_stopped(port)) { s3c24xx_serial_stop_tx(port); - goto out; + return; } /* try and drain the buffer... */ @@ -893,7 +889,7 @@ static irqreturn_t s3c24xx_serial_tx_chars(int irq, void *id) if (!count && dma_count) { s3c24xx_serial_start_tx_dma(ourport, dma_count); - goto out; + return; } if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) { @@ -904,8 +900,18 @@ static irqreturn_t s3c24xx_serial_tx_chars(int irq, void *id) if (uart_circ_empty(xmit)) s3c24xx_serial_stop_tx(port); +} + +static irqreturn_t s3c24xx_serial_tx_irq(int irq, void *id) +{ + struct s3c24xx_uart_port *ourport = id; + struct uart_port *port = &ourport->port; + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + + s3c24xx_serial_tx_chars(ourport); -out: spin_unlock_irqrestore(&port->lock, flags); return IRQ_HANDLED; } @@ -919,11 +925,11 @@ static irqreturn_t s3c64xx_serial_handle_irq(int irq, void *id) irqreturn_t ret = IRQ_HANDLED; if (pend & S3C64XX_UINTM_RXD_MSK) { - ret = s3c24xx_serial_rx_chars(irq, id); + ret = s3c24xx_serial_rx_irq(irq, id); wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_RXD_MSK); } if (pend & S3C64XX_UINTM_TXD_MSK) { - ret = s3c24xx_serial_tx_chars(irq, id); + ret = s3c24xx_serial_tx_irq(irq, id); wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_TXD_MSK); } return ret; @@ -1155,7 +1161,7 @@ static int s3c24xx_serial_startup(struct uart_port *port) ourport->rx_enabled = 1; - ret = request_irq(ourport->rx_irq, s3c24xx_serial_rx_chars, 0, + ret = request_irq(ourport->rx_irq, s3c24xx_serial_rx_irq, 0, s3c24xx_serial_portname(port), ourport); if (ret != 0) { @@ -1169,7 +1175,7 @@ static int s3c24xx_serial_startup(struct uart_port *port) ourport->tx_enabled = 1; - ret = request_irq(ourport->tx_irq, s3c24xx_serial_tx_chars, 0, + ret = request_irq(ourport->tx_irq, s3c24xx_serial_tx_irq, 0, s3c24xx_serial_portname(port), ourport); if (ret) {