From patchwork Thu Sep 14 18:38:15 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Ogness X-Patchwork-Id: 723006 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 79660EEAA62 for ; Thu, 14 Sep 2023 18:41:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242162AbjINSmA (ORCPT ); Thu, 14 Sep 2023 14:42:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37354 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242004AbjINSj6 (ORCPT ); Thu, 14 Sep 2023 14:39:58 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3A88B2139; Thu, 14 Sep 2023 11:39:05 -0700 (PDT) From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1694716743; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0VJ6CgzcUt97Sq6jT/T/98yELCXXHkc/OLg8MuGFujM=; b=2Q8ZWVVt4nOO784XYJxgw1TUsfcdKAz0Y5+p60KtUyCRIsGYdCIskPFE+osS7+MkxwviQt UML2Y73woxFqdZHm6y94vd3WGC56kpgzzzbF2i5Ubc0Aro/OmrgD0CxWgcpFi347G+NQZH h90Lof0AlZsIu85LlPQevIPzRFfD7CrqttJtuQU3DYChU+D751il2UBumt99HaTKqunct/ 26LmtSeaqPDLr1pPNjDhaxBC8MMUkiG9VtRP+NG14Ke6NMcQ0DamBJBgpShKTO0+/7MQDj l510AATKDexz0xJw6MogQYOHDTzUhEwMvTmC02EXbku1B63xHHV0/JriASW0lA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1694716743; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0VJ6CgzcUt97Sq6jT/T/98yELCXXHkc/OLg8MuGFujM=; b=vwvzaothGm7O+kiuENFNt17TWnYKIc4YDYnd1sfg4ZHwAk6rFlSpEEbCz+oonZ6Z7p4V0g 2/A7G8m1pzZF8rBQ== To: Greg Kroah-Hartman Cc: Jiri Slaby , linux-serial@vger.kernel.org, Petr Mladek , Thomas Gleixner , linux-kernel@vger.kernel.org Subject: [PATCH tty v1 58/74] serial: mctrl_gpio: Use port lock wrappers Date: Thu, 14 Sep 2023 20:44:15 +0206 Message-Id: <20230914183831.587273-59-john.ogness@linutronix.de> In-Reply-To: <20230914183831.587273-1-john.ogness@linutronix.de> References: <20230914183831.587273-1-john.ogness@linutronix.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org From: Thomas Gleixner When a serial port is used for kernel console output, then all modifications to the UART registers which are done from other contexts, e.g. getty, termios, are interference points for the kernel console. So far this has been ignored and the printk output is based on the principle of hope. The rework of the console infrastructure which aims to support threaded and atomic consoles, requires to mark sections which modify the UART registers as unsafe. This allows the atomic write function to make informed decisions and eventually to restore operational state. It also allows to prevent the regular UART code from modifying UART registers while printk output is in progress. All modifications of UART registers are guarded by the UART port lock, which provides an obvious synchronization point with the console infrastructure. To avoid adding this functionality to all UART drivers, wrap the spin_[un]lock*() invocations for uart_port::lock into helper functions which just contain the spin_[un]lock*() invocations for now. In a subsequent step these helpers will gain the console synchronization mechanisms. Converted with coccinelle. No functional change. Signed-off-by: Thomas Gleixner --- drivers/tty/serial/serial_mctrl_gpio.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/serial_mctrl_gpio.c b/drivers/tty/serial/serial_mctrl_gpio.c index 7d5aaa8d422b..e51ca593ab86 100644 --- a/drivers/tty/serial/serial_mctrl_gpio.c +++ b/drivers/tty/serial/serial_mctrl_gpio.c @@ -184,7 +184,7 @@ static irqreturn_t mctrl_gpio_irq_handle(int irq, void *context) mctrl_gpio_get(gpios, &mctrl); - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); mctrl_diff = mctrl ^ gpios->mctrl_prev; gpios->mctrl_prev = mctrl; @@ -205,7 +205,7 @@ static irqreturn_t mctrl_gpio_irq_handle(int irq, void *context) wake_up_interruptible(&port->state->port.delta_msr_wait); } - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); return IRQ_HANDLED; }