From patchwork Tue Oct 27 13:55:41 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 312825 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 32D11C64E7C for ; Tue, 27 Oct 2020 14:52:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CAB5D22275 for ; Tue, 27 Oct 2020 14:52:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603810341; bh=Q/+gUd7fHtiCvHIy40Qm0jROcCTe7w9wnxyrntbAVk4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=qnJZj3o+M0kRdEtG8EFco1KigaItwoV3duDyXpZFjyxe9TcwUhkYTnPdpyUAAyh2x mmC6tFf3/1d7AGxBWQ7b931aTLOqwudFhV1F8doyTatDdBA5jMC10DzIPzDh6fPvoC +J92rKZSmlSsepWkdVDCAttJgkGRQt44/Pv6Tudo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764636AbgJ0OrJ (ORCPT ); Tue, 27 Oct 2020 10:47:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:47020 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1764622AbgJ0OrH (ORCPT ); Tue, 27 Oct 2020 10:47:07 -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 1A027206E5; Tue, 27 Oct 2020 14:47:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603810026; bh=Q/+gUd7fHtiCvHIy40Qm0jROcCTe7w9wnxyrntbAVk4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WiioONAUTHX3u68GfZZLdU1L1b+CpG2RA1SrnEL15iB+PzwIdWToarYxMuouOw5sU hpXNTHRv974MTrD5JrvWZ0FA8cnuxImoKBIAydCH3/ckNDJleQ1RTdxigcAFLx1oTS sNKJnMvCTYCO+6cBC17hOlk+dPYjEC85XRalqSaU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Fugang Duan , Peng Fan Subject: [PATCH 5.4 403/408] tty: serial: fsl_lpuart: fix lpuart32_poll_get_char Date: Tue, 27 Oct 2020 14:55:41 +0100 Message-Id: <20201027135513.696350196@linuxfoundation.org> X-Mailer: git-send-email 2.29.1 In-Reply-To: <20201027135455.027547757@linuxfoundation.org> References: <20201027135455.027547757@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 @@ -666,7 +666,7 @@ 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);