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=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 5E34CC43381 for ; Tue, 26 Mar 2019 06:47:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 216BF2070B for ; Tue, 26 Mar 2019 06:47:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553582853; bh=2b+COi1Be/8DesjcBZSZEjv9DzOv+LL10rhyBuaqpKc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=AmioGJyWXF71+JXM8TJLfwhJNeYumYZMwp2K2T+lauvMl3VwZfQ4lWdxKm7c7hRWK j7iwGFnstAXKM+k4B/dXoKQcww41BnA08is/ULp/1Q3r0AGj4hCKTxfhNpyS4uJT5B eoOo5NuvVLpFsjg1am19AnCj7beC4vyAuUwCAPvU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731252AbfCZGb4 (ORCPT ); Tue, 26 Mar 2019 02:31:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:41334 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731215AbfCZGbz (ORCPT ); Tue, 26 Mar 2019 02:31:55 -0400 Received: from localhost (unknown [104.132.152.111]) (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 63BEF20823; Tue, 26 Mar 2019 06:31:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553581914; bh=2b+COi1Be/8DesjcBZSZEjv9DzOv+LL10rhyBuaqpKc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OpCAqUgmJnsP7baI/ZVY9xcT3m49gCGa66E1R2NsVaUeIovWntoW3LncYP077fBIx f9hm6KRLVsoz5EzFtRHhal8Fedbs5PcJN3Oo88Xpc7bq4rpHDZfECwLpSQ0BQg0J32 3QybWaF4/U33QYS1TmFFbMoKRBQz6RMLRnD41d70= 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 4.9 23/30] serial: sprd: clear timeout interrupt only rather than all interrupts Date: Tue, 26 Mar 2019 15:30:02 +0900 Message-Id: <20190326042608.349539737@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190326042607.558087893@linuxfoundation.org> References: <20190326042607.558087893@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: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.9-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))