From patchwork Thu Mar 4 16:23:08 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Erwan LE RAY X-Patchwork-Id: 393251 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, 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 01D1AC4361B for ; Thu, 4 Mar 2021 16:25:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DADC164F51 for ; Thu, 4 Mar 2021 16:25:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237222AbhCDQY0 (ORCPT ); Thu, 4 Mar 2021 11:24:26 -0500 Received: from mx07-00178001.pphosted.com ([185.132.182.106]:39566 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237037AbhCDQYK (ORCPT ); Thu, 4 Mar 2021 11:24:10 -0500 Received: from pps.filterd (m0241204.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 124GB9YJ003292; Thu, 4 Mar 2021 17:23:22 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foss.st.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=selector1; bh=WrtOmysTqy2QzPtzKw9QyQG2otxiyRbpfVahFna0HqQ=; b=XGcR6e7MYDdHi5Vx+jyTwXUZKki2VBOTrfMp88HYfpI221q4NYZT3lRIUNSFI+8wnZpX pUK/lePhaRsirFY8K4tUk1MB5RqTdFJvLIB+KBsab6O48h+W1tWkVlX7GAVORqVNRFPW ERbdy+Rf0IUxWzlFvcbTgyzdqllFx+b0WZfpPwtW/LnzduaBKxEZeoRcQeeeaJPtoPQr FcuBPpGIUZXRy8qjzOvMUDWHPTtxuKd8uoMBdJke54BRuU/5CxCj/W1xtqPMQTLml9sF +QeIpnvMVd21Fv8uaAfAJkLZeI9yqkbPrWPPxSNpk4Q5PSn7719yaUuKTKF5NwOz/A8J fw== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com with ESMTP id 370xej5ays-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 04 Mar 2021 17:23:21 +0100 Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 93D6710002A; Thu, 4 Mar 2021 17:23:21 +0100 (CET) Received: from Webmail-eu.st.com (sfhdag2node3.st.com [10.75.127.6]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 8674420741B; Thu, 4 Mar 2021 17:23:21 +0100 (CET) Received: from localhost (10.75.127.50) by SFHDAG2NODE3.st.com (10.75.127.6) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 4 Mar 2021 17:23:21 +0100 From: Erwan Le Ray To: Greg Kroah-Hartman , Jiri Slaby , Maxime Coquelin , Alexandre Torgue CC: , , , , Erwan Le Ray , Fabrice Gasnier , Valentin Caron Subject: [PATCH v2 13/13] serial: stm32: add support for "flush_buffer" ops Date: Thu, 4 Mar 2021 17:23:08 +0100 Message-ID: <20210304162308.8984-14-erwan.leray@foss.st.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210304162308.8984-1-erwan.leray@foss.st.com> References: <20210304162308.8984-1-erwan.leray@foss.st.com> MIME-Version: 1.0 X-Originating-IP: [10.75.127.50] X-ClientProxiedBy: SFHDAG2NODE3.st.com (10.75.127.6) To SFHDAG2NODE3.st.com (10.75.127.6) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.369, 18.0.761 definitions=2021-03-04_05:2021-03-03,2021-03-04 signatures=0 Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org Add the support for "flush_buffer" ops in order to flush any write buffers, reset any DMA state and stop any ongoing DMA transfers when the port->state->xmit circular buffer is cleared. Signed-off-by: Erwan Le Ray diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index 99dfa884cbef..9db6708e3d9f 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -597,6 +597,19 @@ static void stm32_usart_start_tx(struct uart_port *port) stm32_usart_transmit_chars(port); } +/* Flush the transmit buffer. */ +static void stm32_usart_flush_buffer(struct uart_port *port) +{ + struct stm32_port *stm32_port = to_stm32_port(port); + const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; + + if (stm32_port->tx_ch) { + dmaengine_terminate_async(stm32_port->tx_ch); + stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAT); + stm32_port->tx_dma_busy = false; + } +} + /* Throttle the remote when input buffer is about to overflow. */ static void stm32_usart_throttle(struct uart_port *port) { @@ -992,6 +1005,7 @@ static const struct uart_ops stm32_uart_ops = { .break_ctl = stm32_usart_break_ctl, .startup = stm32_usart_startup, .shutdown = stm32_usart_shutdown, + .flush_buffer = stm32_usart_flush_buffer, .set_termios = stm32_usart_set_termios, .pm = stm32_usart_pm, .type = stm32_usart_type,