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 B2D5AC433FE for ; Tue, 18 Jan 2022 02:43:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240526AbiARCnY (ORCPT ); Mon, 17 Jan 2022 21:43:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59958 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345041AbiARCiQ (ORCPT ); Mon, 17 Jan 2022 21:38:16 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 942B5C061757; Mon, 17 Jan 2022 18:35:02 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 75C4961216; Tue, 18 Jan 2022 02:35:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 05A23C36AEF; Tue, 18 Jan 2022 02:35:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1642473301; bh=kvtpMf09zNVnWWbXCIVl9s/7VjcLSSErZYuDPGmkE3A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=a7cWxdhZZBVWVK+hofbR1qxpMznINBgpc8aUX16IvYKPtFl2WtpiFd3OLe2DJIcls JGn2qZCh8rGC+50pgiJv/huoDpo562KsS7xRFPXY5W6OgumWhCQJ5BExodGvj1Irzf YdXWj++cJolviOL5XGhP6eM5a0COrr8hq24nal/YAlBVUwgNED6LHbdT3lbf1wGNQK rVdKaJWH5wJ/fwFQH/Fe4zHk5k7xSBF5WuwpcZrsrcGfNc+uNNNAnb3Ac0DI9JkROM bp7hYRTz3aTUSSTSEHherYRFl4B1JXJG+NLRPoHpKm9iyDWZcn2cgUl6ajDXE2kdtk mAD4NCOu7fPfg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jiri Slaby , Greg Kroah-Hartman , Sasha Levin , jirislaby@kernel.org, shawnguo@kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH AUTOSEL 5.15 058/188] mxser: keep only !tty test in ISR Date: Mon, 17 Jan 2022 21:29:42 -0500 Message-Id: <20220118023152.1948105-58-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220118023152.1948105-1-sashal@kernel.org> References: <20220118023152.1948105-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jiri Slaby [ Upstream commit 274ab58dc2b460cc474ffc7ccfcede4b2be1a3f5 ] The others are superfluous with tty refcounting in place now. And they are racy in fact: * tty_port_initialized() reports false for a small moment after interrupts are enabled. * closing is 1 while the port is still alive. The queues are flushed later during close anyway. So there is no need for this special handling. Actually, the ISR should not flush the queues. It should behave as every other driver, just queue the chars into tty buffer and go on. But this will be changed later. There is still a lot code depending on having tty in ISR (and not only tty_port). Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20211118073125.12283-4-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/mxser.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c index 1216f3985e18e..da375851af4e6 100644 --- a/drivers/tty/mxser.c +++ b/drivers/tty/mxser.c @@ -261,7 +261,6 @@ struct mxser_port { unsigned int xmit_head; unsigned int xmit_tail; unsigned int xmit_cnt; - int closing; spinlock_t slock; }; @@ -923,7 +922,6 @@ static void mxser_close(struct tty_struct *tty, struct file *filp) return; if (tty_port_close_start(port, tty, filp) == 0) return; - info->closing = 1; mutex_lock(&port->mutex); mxser_close_port(port); mxser_flush_buffer(tty); @@ -932,7 +930,6 @@ static void mxser_close(struct tty_struct *tty, struct file *filp) mxser_shutdown_port(port); tty_port_set_initialized(port, 0); mutex_unlock(&port->mutex); - info->closing = 0; /* Right now the tty_port set is done outside of the close_end helper as we don't yet have everyone using refcounts */ tty_port_close_end(port, tty); @@ -1693,7 +1690,7 @@ static bool mxser_port_isr(struct mxser_port *port) iir &= MOXA_MUST_IIR_MASK; tty = tty_port_tty_get(&port->port); - if (!tty || port->closing || !tty_port_initialized(&port->port)) { + if (!tty) { status = inb(port->ioaddr + UART_LSR); outb(MOXA_MUST_FCR_GDA_MODE_ENABLE | UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT, -- 2.34.1