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 7DC93C4332F for ; Tue, 18 Jan 2022 02:25:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236894AbiARCZS (ORCPT ); Mon, 17 Jan 2022 21:25:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57188 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245307AbiARCXa (ORCPT ); Mon, 17 Jan 2022 21:23:30 -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 D6B67C061751; Mon, 17 Jan 2022 18:23:22 -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 511D260AD6; Tue, 18 Jan 2022 02:23:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CE68CC36AEF; Tue, 18 Jan 2022 02:23:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1642472601; bh=cdFXuFaCObFyYMFaICM/VLalkvjImrTRIgfaj6Fp60w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=C2KpF+ebQXeWwNhscNskuf4CVEt1dVsiOlb4tvNUAIfYfJWNrWKef4mLzLlD5L4XD rEKMExD38/ZJgLXcleY6X8JtnzYBEDXcmOhOVTKJs42dI99NwSOE+fd9UjbwdC2EMX MkJkKXWzswqZFqrmj7BFghD6AA26oq3s5AuTuqCe4fRB/hFGMoe93/oZ3TUkyYQOSE KG9gvLkQnrAjBq+p901jGscyDDk6ZKC+Rpaxgd+GXv9LUe0aaAaO8MtJlPxuNRudrM iJC+9kd3ZZ6B1vTTDA7zgaR6KFo+UchJcgxLJ599svTvTCAheByxW8JngYvGDIjXCn dYGKC8O0Ucc0Q== 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 5.16 066/217] mxser: keep only !tty test in ISR Date: Mon, 17 Jan 2022 21:17:09 -0500 Message-Id: <20220118021940.1942199-66-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220118021940.1942199-1-sashal@kernel.org> References: <20220118021940.1942199-1-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: linux-kernel@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 93a95a135a71a..27caa2f9ba79b 100644 --- a/drivers/tty/mxser.c +++ b/drivers/tty/mxser.c @@ -262,7 +262,6 @@ struct mxser_port { unsigned int xmit_head; unsigned int xmit_tail; unsigned int xmit_cnt; - int closing; spinlock_t slock; }; @@ -918,7 +917,6 @@ 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); @@ -927,7 +925,6 @@ 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); @@ -1683,7 +1680,7 @@ 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(port->FCR | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT, port->ioaddr + UART_FCR); -- 2.34.1