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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 8C56BC43381 for ; Mon, 1 Apr 2019 17:31:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5D2B721852 for ; Mon, 1 Apr 2019 17:31:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554139862; bh=e7tM6KpXWVA7sxsm42uH/FbqIyOrc2da6vRWNVwmr80=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=gr6m910sqPPoXtZmcZRstv2mt3l9Vvq7o31pEBCLzkRhsyBROueY0XRExFy+LNpEg jxe6EzeqGbj+hJKybRP+EiQqQM19Mk7FoM5VyNq2fNT+2bjG9w1gPgjHu7OCQy3NBQ 52ykle7YUNl4k2r7hvgLRr8c4/LEimUNL8pZcgQA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733201AbfDARbB (ORCPT ); Mon, 1 Apr 2019 13:31:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:38216 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733181AbfDARa5 (ORCPT ); Mon, 1 Apr 2019 13:30:57 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 7711120880; Mon, 1 Apr 2019 17:30:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554139857; bh=e7tM6KpXWVA7sxsm42uH/FbqIyOrc2da6vRWNVwmr80=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rskGYGVfccHNI/dTcBymmqWIBm2zULsqs13cNTRWjMaZfgCZmsmY4DUXbXZ+jMYkc ldfylI4ED6S5L32zoz1aTxpopaSWeru0s6NYL53i8B6om4XT/Q0sDevgT98WCS32ri Q2msKZ/HAuzsgi9lVvFa1cEjgnU23IKAVsGd2wvc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lanqing Liu , Chunyan Zhang , Arnd Bergmann Subject: [PATCH 4.4 033/131] serial: sprd: clear timeout interrupt only rather than all interrupts Date: Mon, 1 Apr 2019 19:01:43 +0200 Message-Id: <20190401170054.888536517@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190401170051.645954551@linuxfoundation.org> References: <20190401170051.645954551@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Lanqing Liu commit 4350782570b919f254c1e083261a21c19fcaee90 upstream. On Spreadtrum's serial device, nearly all of interrupts would be cleared by hardware except timeout interrupt. This patch removed the operation of clearing all interrupt in irq handler, instead added an if statement to check if the timeout interrupt is supposed to be cleared. Wrongly clearing timeout interrupt would lead to uart data stay in rx fifo, that means the driver cannot read them out anymore. Signed-off-by: Lanqing Liu Signed-off-by: Chunyan Zhang Signed-off-by: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/sprd_serial.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/tty/serial/sprd_serial.c +++ b/drivers/tty/serial/sprd_serial.c @@ -63,6 +63,7 @@ /* interrupt clear register */ #define SPRD_ICLR 0x0014 +#define SPRD_ICLR_TIMEOUT BIT(13) /* line control register */ #define SPRD_LCR 0x0018 @@ -298,7 +299,8 @@ static irqreturn_t sprd_handle_irq(int i return IRQ_NONE; } - serial_out(port, SPRD_ICLR, ~0); + if (ims & SPRD_IMSR_TIMEOUT) + serial_out(port, SPRD_ICLR, SPRD_ICLR_TIMEOUT); if (ims & (SPRD_IMSR_RX_FIFO_FULL | SPRD_IMSR_BREAK_DETECT | SPRD_IMSR_TIMEOUT))