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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 85360C28B27 for ; Thu, 9 Sep 2021 13:07:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 66BEB61216 for ; Thu, 9 Sep 2021 13:07:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352435AbhIINHz (ORCPT ); Thu, 9 Sep 2021 09:07:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:46028 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351554AbhIIMtG (ORCPT ); Thu, 9 Sep 2021 08:49:06 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id A649F61051; Thu, 9 Sep 2021 11:56:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631188599; bh=31chLHWe85bUi+JEnDwBmhCPpyPFPd0LQK87sK9/VtM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=j2DzPeDprY+MCLSVE/T5AaD8uUPJJw36oqW0KacpnbrX4Q1QYNDtwxMwZ8opOX5FJ yMjlJXw9td7zlm8PbZGICTbbmjIZI/H69d06JW4g468yQCJRUQKdImCiWQKXtd9jPH qTDdqIoLdsE+WUB3r5w516aIzQCmGEz4KGbY9FttO9G7cpFTYFR0K5SxFRpDxPl0gm iIiZ7LTN0NKL7rWK51i8WOQqJPbxaZGJXXMnoJox2pIC+8FFLMr9D4JKUHBpz7FtzC 7EvZx4UAXjhn52kECAQeQV9D0Y9K5TKYJHe6t7rXpn/Z06Sz9yvELxuIWcNwV0EdvI JRc9fLSgjC4gA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ulrich Hecht , Greg Kroah-Hartman , Sasha Levin , linux-serial@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 072/109] serial: sh-sci: fix break handling for sysrq Date: Thu, 9 Sep 2021 07:54:29 -0400 Message-Id: <20210909115507.147917-72-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210909115507.147917-1-sashal@kernel.org> References: <20210909115507.147917-1-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: Ulrich Hecht [ Upstream commit 87b8061bad9bd4b549b2daf36ffbaa57be2789a2 ] This fixes two issues that cause the sysrq sequence to be inadvertently aborted on SCIF serial consoles: - a NUL character remains in the RX queue after a break has been detected, which is then passed on to uart_handle_sysrq_char() - the break interrupt is handled twice on controllers with multiplexed ERI and BRI interrupts Signed-off-by: Ulrich Hecht Link: https://lore.kernel.org/r/20210816162201.28801-1-uli+renesas@fpond.eu Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/sh-sci.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 97ee1fc1cd24..ecff9b208808 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1763,6 +1763,10 @@ static irqreturn_t sci_br_interrupt(int irq, void *ptr) /* Handle BREAKs */ sci_handle_breaks(port); + + /* drop invalid character received before break was detected */ + serial_port_in(port, SCxRDR); + sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port)); return IRQ_HANDLED; @@ -1842,7 +1846,8 @@ static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr) ret = sci_er_interrupt(irq, ptr); /* Break Interrupt */ - if ((ssr_status & SCxSR_BRK(port)) && err_enabled) + if (s->irqs[SCIx_ERI_IRQ] != s->irqs[SCIx_BRI_IRQ] && + (ssr_status & SCxSR_BRK(port)) && err_enabled) ret = sci_br_interrupt(irq, ptr); /* Overrun Interrupt */ -- 2.30.2