From patchwork Fri Dec 16 11:53:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marek Vasut X-Patchwork-Id: 635385 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 018C6C4332F for ; Fri, 16 Dec 2022 11:53:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230284AbiLPLx5 (ORCPT ); Fri, 16 Dec 2022 06:53:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48838 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229905AbiLPLx4 (ORCPT ); Fri, 16 Dec 2022 06:53:56 -0500 Received: from phobos.denx.de (phobos.denx.de [85.214.62.61]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 71D7B2F670 for ; Fri, 16 Dec 2022 03:53:51 -0800 (PST) Received: from tr.lan (ip-86-49-120-218.bb.vodafone.cz [86.49.120.218]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: marex@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id A0EAE839D5; Fri, 16 Dec 2022 12:53:49 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1671191630; bh=2mCUSi2l1mAANnGndtPDX69+rLa/kGsnNIcZ7tM4MG8=; h=From:To:Cc:Subject:Date:From; b=Y6vHA4ZJnEo5dvItgrNDU4BWSpmBoegqQU9yJFjLlmsbfdysVhxed2Lho/S91KNeX kEp3tTvhWRutZ3eKsYLvVCZ9BawEK+Q14K+qFw0vIuaU985F7Vh5S5BCSMk0vNYWHi qjtEIOwkbwa2OFQJqhkGCmRO+kMT1sMQsYxnaXXD+DrTWdKEh5q8Vo6HGMlbZ5xXzH h4coIdNHSdURHjGhZ6SITRqhCL5ux158x+uoDuztZI4c2MDAwcmw0xTQM9TEu0keue DQNYBqObkd90GI0QHqbgprcImuj9H6oXNia6Ve6RUJcZsSik8Fvmj21Yi67hLUZGtL DFtpewhF6Zk+Q== From: Marek Vasut To: linux-serial@vger.kernel.org Cc: Marek Vasut , Sebastian Andrzej Siewior , Alexandre Torgue , Erwan Le Ray , Greg Kroah-Hartman , Jiri Slaby , Maxime Coquelin , Thomas Gleixner , Valentin Caron , linux-arm-kernel@lists.infradead.org, linux-stm32@st-md-mailman.stormreply.com Subject: [PATCH v3] serial: stm32: Merge hard IRQ and threaded IRQ handling into single IRQ handler Date: Fri, 16 Dec 2022 12:53:38 +0100 Message-Id: <20221216115338.7150-1-marex@denx.de> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 X-Virus-Scanned: clamav-milter 0.103.6 at phobos.denx.de X-Virus-Status: Clean Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org Requesting an interrupt with IRQF_ONESHOT will run the primary handler in the hard-IRQ context even in the force-threaded mode. The force-threaded mode is used by PREEMPT_RT in order to avoid acquiring sleeping locks (spinlock_t) in hard-IRQ context. This combination makes it impossible and leads to "sleeping while atomic" warnings. Use one interrupt handler for both handlers (primary and secondary) and drop the IRQF_ONESHOT flag which is not needed. Fixes: e359b4411c283 ("serial: stm32: fix threaded interrupt handling") Reviewed-by: Sebastian Andrzej Siewior Signed-off-by: Marek Vasut Tested-by: Valentin Caron --- Cc: Alexandre Torgue Cc: Erwan Le Ray Cc: Greg Kroah-Hartman Cc: Jiri Slaby Cc: Maxime Coquelin Cc: Sebastian Andrzej Siewior Cc: Thomas Gleixner Cc: Valentin Caron Cc: linux-arm-kernel@lists.infradead.org Cc: linux-stm32@st-md-mailman.stormreply.com To: linux-serial@vger.kernel.org --- V2: - Update patch subject, was: serial: stm32: Move hard IRQ handling to threaded interrupt context - Use request_irq() instead, rename the IRQ handler function V3: - Update the commit message per suggestion from Sebastian - Add RB from Sebastian - Add Fixes tag --- drivers/tty/serial/stm32-usart.c | 29 +++++++---------------------- 1 file changed, 7 insertions(+), 22 deletions(-) diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index dfdbcf092facc..bbbab8dc2bfa9 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -752,8 +752,9 @@ static irqreturn_t stm32_usart_interrupt(int irq, void *ptr) struct tty_port *tport = &port->state->port; struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; - u32 sr; + unsigned long flags; unsigned int size; + u32 sr; sr = readl_relaxed(port->membase + ofs->isr); @@ -793,27 +794,13 @@ static irqreturn_t stm32_usart_interrupt(int irq, void *ptr) } if ((sr & USART_SR_TXE) && !(stm32_port->tx_ch)) { - spin_lock(&port->lock); + spin_lock_irqsave(&port->lock, flags); stm32_usart_transmit_chars(port); - spin_unlock(&port->lock); + spin_unlock_irqrestore(&port->lock, flags); } - if (stm32_usart_rx_dma_enabled(port)) - return IRQ_WAKE_THREAD; - else - return IRQ_HANDLED; -} - -static irqreturn_t stm32_usart_threaded_interrupt(int irq, void *ptr) -{ - struct uart_port *port = ptr; - struct tty_port *tport = &port->state->port; - struct stm32_port *stm32_port = to_stm32_port(port); - unsigned int size; - unsigned long flags; - /* Receiver timeout irq for DMA RX */ - if (!stm32_port->throttled) { + if (stm32_usart_rx_dma_enabled(port) && !stm32_port->throttled) { spin_lock_irqsave(&port->lock, flags); size = stm32_usart_receive_chars(port, false); uart_unlock_and_check_sysrq_irqrestore(port, flags); @@ -1016,10 +1003,8 @@ static int stm32_usart_startup(struct uart_port *port) u32 val; int ret; - ret = request_threaded_irq(port->irq, stm32_usart_interrupt, - stm32_usart_threaded_interrupt, - IRQF_ONESHOT | IRQF_NO_SUSPEND, - name, port); + ret = request_irq(port->irq, stm32_usart_interrupt, + IRQF_NO_SUSPEND, name, port); if (ret) return ret;