From mboxrd@z Thu Jan 1 00:00:00 1970 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 731FCC0015E for ; Fri, 11 Aug 2023 06:43:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230123AbjHKGnq (ORCPT ); Fri, 11 Aug 2023 02:43:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52342 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231214AbjHKGnp (ORCPT ); Fri, 11 Aug 2023 02:43:45 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4A9802D41; Thu, 10 Aug 2023 23:43:45 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id DEFD865416; Fri, 11 Aug 2023 06:43:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D6678C433C8; Fri, 11 Aug 2023 06:43:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1691736224; bh=Ls2zMPANCq4n8zcJeSklRLY1qQY2H5Ysy9vX31ySfT4=; h=From:To:Cc:Subject:Date:From; b=XZu5TEFPZdnjEgq64XK4X+7flyOxSLEOspoKVljn28erlKLykZx3CH1jcrR4kUYIx 3qk34mHOa7MkqBWaBW9RwipcwtdbFPSBHQPqMuBd6C/oehqRAAaPOh6u/Fbt0sV2qH nXiBx3KmiloGJ5gbB0nqfySWPdopNpIeByYW9MJpVCL0RdglwtbfK1PH+6FcbjO5TD pKFCGEOEd8ZNLDAKykyk98JR0RA3AZUKp+VivaZBmPbNwZtG2OV/h7iEGwpv7/SQk3 FOmz4YwTnDSZopSYli2YAzQb+DX9Q4kH0zGAo/YU2AM6h+vQnf9Sl4/HsCmxrkvSAm mtEVx3UNtDJ/g== From: "Jiri Slaby (SUSE)" To: gregkh@linuxfoundation.org Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, "Jiri Slaby (SUSE)" , Vlastimil Babka , John Ogness Subject: [PATCH] serial: 8250: drop lockdep annotation from serial8250_clear_IER() Date: Fri, 11 Aug 2023 08:43:40 +0200 Message-ID: <20230811064340.13400-1-jirislaby@kernel.org> X-Mailer: git-send-email 2.41.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org The port lock is not always held when calling serial8250_clear_IER(). When an oops is in progress, the lock is tried to be taken and when it is not, a warning is issued: WARNING: CPU: 0 PID: 1 at drivers/tty/serial/8250/8250_port.c:707 +0x57/0x60 Modules linked in: CPU: 0 PID: 1 Comm: init Not tainted 6.5.0-rc5-1.g225bfb7-default+ #774 00f1be860db663ed29479b8255d3b01ab1135bd3 Hardware name: QEMU Standard PC ... RIP: 0010:serial8250_clear_IER+0x57/0x60 ... Call Trace: serial8250_console_write+0x9e/0x4b0 console_flush_all+0x217/0x5f0 ... Therefore, remove the annotation as it doesn't hold for all invocations. The other option would be to make the lockdep test conditional on 'oops_in_progress' or pass 'locked' from serial8250_console_write(). I don't think, that is worth it. Signed-off-by: Jiri Slaby (SUSE) Reported-by: Vlastimil Babka Cc: John Ogness Fixes: d0b309a5d3f4 (serial: 8250: synchronize and annotate UART_IER access) --- drivers/tty/serial/8250/8250_port.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index ecfdc4534123..f59328e1c35d 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -703,9 +703,6 @@ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep) static void serial8250_clear_IER(struct uart_8250_port *up) { - /* Port locked to synchronize UART_IER access against the console. */ - lockdep_assert_held_once(&up->port.lock); - if (up->capabilities & UART_CAP_UUE) serial_out(up, UART_IER, UART_IER_UUE); else -- 2.41.0