From nobody Mon Feb 9 03:45:54 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E9B42C04A6A for ; Thu, 3 Aug 2023 13:03:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233884AbjHCNDh (ORCPT ); Thu, 3 Aug 2023 09:03:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53564 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235328AbjHCNDc (ORCPT ); Thu, 3 Aug 2023 09:03:32 -0400 Received: from mx07-00178001.pphosted.com (mx08-00178001.pphosted.com [91.207.212.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E17B14226; Thu, 3 Aug 2023 06:03:15 -0700 (PDT) Received: from pps.filterd (m0046661.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.17.1.22/8.17.1.22) with ESMTP id 373CeVra009018; Thu, 3 Aug 2023 15:03:02 +0200 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-transfer-encoding:content-type; s= selector1; bh=8u4d3LvlGUVXnqclczmcYRVp1j8VsBGa+/jN0gq0QF0=; b=qx te2mDKZaPpbobyPTxf0NdlqR2169gtOYY18MhJjhEjNZY6GEnwi8Z0s88d9612z+ OsFanHq7SWUNkvFf2pukLcghm7v8f07jfdTdZTFEg1ruwET0nUEzjjY5IFtEbEZZ GGIv2x236sUW5JBLLjkYbZMXq1I6BMp3Z1eQR1IVsSiCaZiXNjDcqP+6sv1HK+ZK 6fxFp4AIqdy3+duOaPrPam+5m45dd0WYPTDI9TFmfiGvQL5sQx5YH7nVgFlYdGY8 CixfIJlNMqiD9lMmm4X2YkivSLbbNGECCKoCum6f6OjyFRHdh7PNvNkFjo7mtT8E N8s2y9Rtqgy8iOcBmJew== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com (PPS) with ESMTPS id 3s8cet04np-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 03 Aug 2023 15:03:02 +0200 (MEST) Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 419B010008B; Thu, 3 Aug 2023 15:03:02 +0200 (CEST) Received: from Webmail-eu.st.com (shfdag1node1.st.com [10.75.129.69]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 389C62207B5; Thu, 3 Aug 2023 15:03:02 +0200 (CEST) Received: from localhost (10.201.20.168) by SHFDAG1NODE1.st.com (10.75.129.69) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.21; Thu, 3 Aug 2023 15:03:01 +0200 From: Valentin Caron To: Greg Kroah-Hartman CC: Jiri Slaby , Alexandre Torgue , Amelie Delaunay , , , , , Valentin Caron Subject: [PATCH 6/6] serial: stm32: synchronize RX DMA channel in shutdown Date: Thu, 3 Aug 2023 15:01:34 +0200 Message-ID: <20230803130134.155355-7-valentin.caron@foss.st.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230803130134.155355-1-valentin.caron@foss.st.com> References: <20230803130134.155355-1-valentin.caron@foss.st.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.201.20.168] X-ClientProxiedBy: SHFCAS1NODE2.st.com (10.75.129.73) To SHFDAG1NODE1.st.com (10.75.129.69) X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.267,Aquarius:18.0.957,Hydra:6.0.591,FMLib:17.11.176.26 definitions=2023-08-03_12,2023-08-03_01,2023-05-22_02 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Amelie Delaunay In shutdown, RX DMA channel is terminated. If the DMA RX callback is scheduled but not yet executed, while a new RX DMA transfer is started, the callback can be executed, and then disturb the ongoing RX DMA transfer. To avoid such a case, call dmaengine_synchronize in shutdown, after the DMA RX channel is terminated. Signed-off-by: Amelie Delaunay --- drivers/tty/serial/stm32-usart.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-us= art.c index 8fc0526be898..5e9cf0c48813 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -1123,8 +1123,10 @@ static void stm32_usart_shutdown(struct uart_port *p= ort) dev_err(port->dev, "Transmission is not complete\n"); =20 /* Disable RX DMA. */ - if (stm32_port->rx_ch) + if (stm32_port->rx_ch) { stm32_usart_rx_dma_terminate(stm32_port); + dmaengine_synchronize(stm32_port->rx_ch); + } =20 /* flush RX & TX FIFO */ if (ofs->rqr !=3D UNDEF_REG) --=20 2.25.1