From patchwork Mon Feb 15 12:17:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hector Martin X-Patchwork-Id: 383035 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, 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 9C976C433E0 for ; Mon, 15 Feb 2021 12:20:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 70AF764E32 for ; Mon, 15 Feb 2021 12:20:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230291AbhBOMU1 (ORCPT ); Mon, 15 Feb 2021 07:20:27 -0500 Received: from marcansoft.com ([212.63.210.85]:43122 "EHLO mail.marcansoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230263AbhBOMUQ (ORCPT ); Mon, 15 Feb 2021 07:20:16 -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 5D4D542529; Mon, 15 Feb 2021 12:19:08 +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 , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 19/25] tty: serial: samsung_tty: IRQ rework Date: Mon, 15 Feb 2021 21:17:07 +0900 Message-Id: <20210215121713.57687-20-marcan@marcan.st> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210215121713.57687-1-marcan@marcan.st> References: <20210215121713.57687-1-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. * For S3C64xx, return IRQ_NONE if no flag bits were set, so the interrupt core can detect IRQ storms. Note that both IRQ handlers always return IRQ_HANDLED anyway, so 'or' logic isn't necessary here, if either handler ran we are always going to return IRQ_HANDLED. * 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 --- drivers/tty/serial/samsung_tty.c | 41 +++++++++++++++++++------------- 1 file changed, 24 insertions(+), 17 deletions(-) diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c index 21955be680a4..821cd0e4f870 100644 --- a/drivers/tty/serial/samsung_tty.c +++ b/drivers/tty/serial/samsung_tty.c @@ -151,6 +151,9 @@ struct s3c24xx_uart_port { #endif }; +static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport); +static void s3c24xx_serial_tx_chars(struct s3c24xx_uart_port *ourport); + /* conversion functions */ #define s3c24xx_dev_to_port(__dev) dev_get_drvdata(__dev) @@ -316,8 +319,6 @@ static void s3c24xx_serial_stop_tx(struct uart_port *port) ourport->tx_mode = 0; } -static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport); - static void s3c24xx_serial_tx_dma_complete(void *args) { struct s3c24xx_uart_port *ourport = args; @@ -825,7 +826,7 @@ 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; @@ -834,16 +835,12 @@ 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 && @@ -860,7 +857,7 @@ 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 @@ -869,7 +866,7 @@ 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... */ @@ -891,7 +888,7 @@ 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) { @@ -902,8 +899,18 @@ 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; } @@ -914,14 +921,14 @@ static irqreturn_t s3c64xx_serial_handle_irq(int irq, void *id) struct s3c24xx_uart_port *ourport = id; struct uart_port *port = &ourport->port; unsigned int pend = rd_regl(port, S3C64XX_UINTP); - irqreturn_t ret = IRQ_HANDLED; + irqreturn_t ret = IRQ_NONE; 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; @@ -1153,7 +1160,7 @@ 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) { @@ -1167,7 +1174,7 @@ 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) {