From patchwork Thu Mar 4 16:22:59 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: 394099 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 BC5CDC433DB for ; Thu, 4 Mar 2021 16:25:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8D47464F4C for ; Thu, 4 Mar 2021 16:25:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237043AbhCDQYU (ORCPT ); Thu, 4 Mar 2021 11:24:20 -0500 Received: from mx08-00178001.pphosted.com ([91.207.212.93]:21732 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S237009AbhCDQYF (ORCPT ); Thu, 4 Mar 2021 11:24:05 -0500 Received: from pps.filterd (m0046660.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 124GC7TP025852; Thu, 4 Mar 2021 17:23:15 +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=LrqFGFtIPN4XqFcQ/wjY4R2i5IBBzhaHbJZTJX35zLk=; b=UC3R/FNqME7OLcHDWzlmUVtky/k8J95GmDFQk2irgywlObBeGL6kLQD9rCHbx65X2CtD Noj4m+9UGObsDuVm/kko+3U+44qiYPTpdveptXog8PBSXEwZTgYqtuK6L5UkVNjuBjat V5aJAI5p7wQEFmwtVQ5DHMoG7nruWTeY7/nWgWhZjfUPyTuUrKRTlhy7z0mdkSCSQrdB ZMq35If1YkGvambqXKgMFn5iWjvVVO95L1UuoFwlvHNFta+cpJQeNLEAV6ya2PqSQaUx Dm48B+Eco7xYhITgOxvzsgu4EwLfgp7312ceGtV1KZUbU3XGQbD0Ciogi3sihEUNRxC6 Qg== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com with ESMTP id 36yfdygh3a-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 04 Mar 2021 17:23:15 +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 DC42510002A; Thu, 4 Mar 2021 17:23:14 +0100 (CET) Received: from Webmail-eu.st.com (sfhdag2node3.st.com [10.75.127.6]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id CED0920741B; Thu, 4 Mar 2021 17:23:14 +0100 (CET) Received: from localhost (10.75.127.48) by SFHDAG2NODE3.st.com (10.75.127.6) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 4 Mar 2021 17:23:14 +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 04/13] serial: stm32: fix TX and RX FIFO thresholds Date: Thu, 4 Mar 2021 17:22:59 +0100 Message-ID: <20210304162308.8984-5-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: [10.75.127.48] 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 TX and RX FIFO thresholds may be cleared after suspend/resume, depending on the low power mode. Those configurations (done in startup) are not effective for UART console, as: - the reference manual indicates that FIFOEN bit can only be written when the USART is disabled (UE=0) - a set_termios (where UE is set) is requested firstly for console enabling, before the startup. Fixes: 84872dc448fe ("serial: stm32: add RX and TX FIFO flush") Signed-off-by: Erwan Le Ray diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index eae54b8cf5e2..223cec70c57c 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -649,19 +649,8 @@ static int stm32_usart_startup(struct uart_port *port) if (ofs->rqr != UNDEF_REG) stm32_usart_set_bits(port, ofs->rqr, USART_RQR_RXFRQ); - /* Tx and RX FIFO configuration */ - if (stm32_port->fifoen) { - val = readl_relaxed(port->membase + ofs->cr3); - val &= ~(USART_CR3_TXFTCFG_MASK | USART_CR3_RXFTCFG_MASK); - val |= USART_CR3_TXFTCFG_HALF << USART_CR3_TXFTCFG_SHIFT; - val |= USART_CR3_RXFTCFG_HALF << USART_CR3_RXFTCFG_SHIFT; - writel_relaxed(val, port->membase + ofs->cr3); - } - - /* RX FIFO enabling */ + /* RX enabling */ val = stm32_port->cr1_irq | USART_CR1_RE | BIT(cfg->uart_enable_bit); - if (stm32_port->fifoen) - val |= USART_CR1_FIFOEN; stm32_usart_set_bits(port, ofs->cr1, val); return 0; @@ -770,9 +759,15 @@ static void stm32_usart_set_termios(struct uart_port *port, if (stm32_port->fifoen) cr1 |= USART_CR1_FIFOEN; cr2 = 0; + + /* Tx and RX FIFO configuration */ cr3 = readl_relaxed(port->membase + ofs->cr3); - cr3 &= USART_CR3_TXFTIE | USART_CR3_RXFTCFG_MASK | USART_CR3_RXFTIE - | USART_CR3_TXFTCFG_MASK; + cr3 &= USART_CR3_TXFTIE | USART_CR3_RXFTIE; + if (stm32_port->fifoen) { + cr3 &= ~(USART_CR3_TXFTCFG_MASK | USART_CR3_RXFTCFG_MASK); + cr3 |= USART_CR3_TXFTCFG_HALF << USART_CR3_TXFTCFG_SHIFT; + cr3 |= USART_CR3_RXFTCFG_HALF << USART_CR3_RXFTCFG_SHIFT; + } if (cflag & CSTOPB) cr2 |= USART_CR2_STOP_2B;