From patchwork Wed May 12 14:43:55 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 436781 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=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, 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 9D8B7C43470 for ; Wed, 12 May 2021 16:02:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7D79261E26 for ; Wed, 12 May 2021 16:02:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236924AbhELQC7 (ORCPT ); Wed, 12 May 2021 12:02:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:37076 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238203AbhELP5b (ORCPT ); Wed, 12 May 2021 11:57:31 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id A9D6261439; Wed, 12 May 2021 15:30:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620833458; bh=h44MHavJuuArjrpAwtzhkwqsgKm4E5Xw3coWdkO0kow=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2EXcrOnZSDF+Empv3XW6fSZ9ojioQLigPGbSpSnjGIzmHD4kRQCvZ8uGMw+WahShH 9LL/xcRU1wie3a2Q4NdpM/MbAaSesZ3ZtzbrN95QeS2Z8kBX0unElIBVztOvM8dcAo 80/7rf5jPwxwMku6yltrA4d0jrgO7x1lVkCHB2LE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Erwan Le Ray , Sasha Levin Subject: [PATCH 5.11 158/601] serial: stm32: fix tx_empty condition Date: Wed, 12 May 2021 16:43:55 +0200 Message-Id: <20210512144833.039430874@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210512144827.811958675@linuxfoundation.org> References: <20210512144827.811958675@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Erwan Le Ray [ Upstream commit 3db1d52466dc11dca4e47ef12a6e6e97f846af62 ] In "tx_empty", we should poll TC bit in both DMA and PIO modes (instead of TXE) to check transmission data register has been transmitted independently of the FIFO mode. TC indicates that both transmit register and shift register are empty. When shift register is empty, tx_empty should return TIOCSER_TEMT instead of TC value. Cleans the USART_CR_TC TCCF register define (transmission complete clear flag) as it is duplicate of USART_ICR_TCCF. Fixes: 48a6092fb41f ("serial: stm32-usart: Add STM32 USART Driver") Signed-off-by: Erwan Le Ray Link: https://lore.kernel.org/r/20210304162308.8984-13-erwan.leray@foss.st.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/stm32-usart.c | 5 ++++- drivers/tty/serial/stm32-usart.h | 3 --- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index cb8c2bece6d6..2cf9fc915510 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -514,7 +514,10 @@ static unsigned int stm32_usart_tx_empty(struct uart_port *port) struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; - return readl_relaxed(port->membase + ofs->isr) & USART_SR_TXE; + if (readl_relaxed(port->membase + ofs->isr) & USART_SR_TC) + return TIOCSER_TEMT; + + return 0; } static void stm32_usart_set_mctrl(struct uart_port *port, unsigned int mctrl) diff --git a/drivers/tty/serial/stm32-usart.h b/drivers/tty/serial/stm32-usart.h index cb4f327c46db..94b568aa46bb 100644 --- a/drivers/tty/serial/stm32-usart.h +++ b/drivers/tty/serial/stm32-usart.h @@ -127,9 +127,6 @@ struct stm32_usart_info stm32h7_info = { /* Dummy bits */ #define USART_SR_DUMMY_RX BIT(16) -/* USART_ICR (F7) */ -#define USART_CR_TC BIT(6) - /* USART_DR */ #define USART_DR_MASK GENMASK(8, 0)