From patchwork Tue Oct 27 13:50:42 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 311807 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=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY,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 8B45FC55178 for ; Tue, 27 Oct 2020 18:08:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4285920790 for ; Tue, 27 Oct 2020 18:08:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603822105; bh=amTksholHYaP6V3+fRmuESgR76MxgK1BjgKQ7sYOYLg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=IMvzn0QqtC2Sybs4L/QHTihoF2RnLCYsLWba8a7FQutEE2Wl6Jh2zaUQRXR8c4a6w ME+iq7lHtSeOcTIGfj+vY8dp/6KbdPn1hlofavA9SvU0gtDtJcYEF4jElrmTLMm3P0 F/OSdmJN8xEx45kr25X53Mkt4xiCyWnktTIR3Kvc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1825065AbgJ0SIV (ORCPT ); Tue, 27 Oct 2020 14:08:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:38388 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2508860AbgJ0OQW (ORCPT ); Tue, 27 Oct 2020 10:16:22 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 572CF2076A; Tue, 27 Oct 2020 14:16:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603808181; bh=amTksholHYaP6V3+fRmuESgR76MxgK1BjgKQ7sYOYLg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UnuIgXFyJC8EqEr/zf68glCU1wG5WFL+qFMSeEecVMHWZaV+e5+thbI0hD06hQFOn wp7yVcdOu8uBSBF2gTlj/0QRvT/d1sJ3zo1EfdkxdGB1X/qBG9kZkDFsteOA7HpeEh uzw9W6wJFYOf/tYAvG/GYMwudUEmGaRnfwWAXXTA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Fugang Duan , Peng Fan Subject: [PATCH 4.14 187/191] tty: serial: fsl_lpuart: fix lpuart32_poll_get_char Date: Tue, 27 Oct 2020 14:50:42 +0100 Message-Id: <20201027134918.715220865@linuxfoundation.org> X-Mailer: git-send-email 2.29.1 In-Reply-To: <20201027134909.701581493@linuxfoundation.org> References: <20201027134909.701581493@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Peng Fan commit 29788ab1d2bf26c130de8f44f9553ee78a27e8d5 upstream. The watermark is set to 1, so we need to input two chars to trigger RDRF using the original logic. With the new logic, we could always get the char when there is data in FIFO. Suggested-by: Fugang Duan Signed-off-by: Peng Fan Link: https://lore.kernel.org/r/20200929095509.21680-1-peng.fan@nxp.com Cc: stable Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/fsl_lpuart.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -567,7 +567,7 @@ static void lpuart32_poll_put_char(struc static int lpuart32_poll_get_char(struct uart_port *port) { - if (!(lpuart32_read(port, UARTSTAT) & UARTSTAT_RDRF)) + if (!(lpuart32_read(port, UARTWATER) >> UARTWATER_RXCNT_OFF)) return NO_POLL_CHAR; return lpuart32_read(port, UARTDATA);