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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 77919C2D0A3 for ; Tue, 3 Nov 2020 20:47:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2CBA222409 for ; Tue, 3 Nov 2020 20:47:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604436469; bh=4iIu57LZw99xO5TmaDLQ9Qk6BI5wQNdxRHxlLCn9hHE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=cPiooDgmMUlRhdQDSdbfqLVsP0kQa3aMdxQky6Lm3rPmKZX1rDw4Fehe+4yhvm896 iBQw9AoCfs8fbehSQudSojc9Ug0UFwKjyyxaJretcLOPv4TkLZK9PluCKGFo79QPUs Yv3+2l1eeSwiQNmJplX495SheEf37INJ7O1jdKFY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731393AbgKCUrs (ORCPT ); Tue, 3 Nov 2020 15:47:48 -0500 Received: from mail.kernel.org ([198.145.29.99]:38386 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731381AbgKCUro (ORCPT ); Tue, 3 Nov 2020 15:47:44 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 270AC20719; Tue, 3 Nov 2020 20:47:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604436463; bh=4iIu57LZw99xO5TmaDLQ9Qk6BI5wQNdxRHxlLCn9hHE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DVdajZ/TxltMi+ZnRegGJomz/a4gDEbOfxIzoDxs9rzYa79wOsk3sX8O2oiLdXN5k gK0s2A8vJ+EEogSeaDPLuwOyqyA5eIMaRA7Fp/+qODEdOegwqpcAK0lB3ZHMFvwniC 9BqqszM8h59jDBXny3wnwzVCTvL3VKuW1NIj1kbA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Russell King Subject: [PATCH 5.9 259/391] tty: serial: 21285: fix lockup on open Date: Tue, 3 Nov 2020 21:35:10 +0100 Message-Id: <20201103203404.500668101@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201103203348.153465465@linuxfoundation.org> References: <20201103203348.153465465@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Russell King commit 82776f6c75a90e1d2103e689b84a689de8f1aa02 upstream. Commit 293f89959483 ("tty: serial: 21285: stop using the unused[] variable from struct uart_port") introduced a bug which stops the transmit interrupt being disabled when there are no characters to transmit - disabling the transmit interrupt at the interrupt controller is the only way to stop an interrupt storm. If this interrupt is not disabled when there are no transmit characters, we end up with an interrupt storm which prevents the machine making forward progress. Fixes: 293f89959483 ("tty: serial: 21285: stop using the unused[] variable from struct uart_port") Signed-off-by: Russell King Cc: stable Link: https://lore.kernel.org/r/E1kU4GS-0006lE-OO@rmk-PC.armlinux.org.uk Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/21285.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) --- a/drivers/tty/serial/21285.c +++ b/drivers/tty/serial/21285.c @@ -50,25 +50,25 @@ static const char serial21285_name[] = " static bool is_enabled(struct uart_port *port, int bit) { - unsigned long private_data = (unsigned long)port->private_data; + unsigned long *private_data = (unsigned long *)&port->private_data; - if (test_bit(bit, &private_data)) + if (test_bit(bit, private_data)) return true; return false; } static void enable(struct uart_port *port, int bit) { - unsigned long private_data = (unsigned long)port->private_data; + unsigned long *private_data = (unsigned long *)&port->private_data; - set_bit(bit, &private_data); + set_bit(bit, private_data); } static void disable(struct uart_port *port, int bit) { - unsigned long private_data = (unsigned long)port->private_data; + unsigned long *private_data = (unsigned long *)&port->private_data; - clear_bit(bit, &private_data); + clear_bit(bit, private_data); } #define is_tx_enabled(port) is_enabled(port, tx_enabled_bit)