From patchwork Mon Jan 31 10:55:13 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 538846 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 634E4C433F5 for ; Mon, 31 Jan 2022 11:11:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348548AbiAaLL0 (ORCPT ); Mon, 31 Jan 2022 06:11:26 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:56974 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1376667AbiAaLIv (ORCPT ); Mon, 31 Jan 2022 06:08:51 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 1455AB82A4E; Mon, 31 Jan 2022 11:08:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 62E17C340E8; Mon, 31 Jan 2022 11:08:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643627328; bh=Ptmp80Y5+Ak9glksGMpn04O9rsKaxAULBmUBfj8gucw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=z8FIQfnCqUgbi4QHAiSRIXEvZj/RwOLQ4+JOS3bOmsxQ7ZLejHVeqmQLO3+VnAcDN 4ghAjzjgZ8T1Ss6/+7N1So5ECx7doAgOg/gTjbgW4gLcrJkrfykQsNafSr9yIITOSO mV+pPQYnr+DqIH0Tw7HNL6q3FpsW6WqVjNh384Hw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Erwan Le Ray , Valentin Caron Subject: [PATCH 5.15 048/171] serial: stm32: fix software flow control transfer Date: Mon, 31 Jan 2022 11:55:13 +0100 Message-Id: <20220131105231.650554206@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220131105229.959216821@linuxfoundation.org> References: <20220131105229.959216821@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Valentin Caron commit 037b91ec7729524107982e36ec4b40f9b174f7a2 upstream. x_char is ignored by stm32_usart_start_tx() when xmit buffer is empty. Fix start_tx condition to allow x_char to be sent. Fixes: 48a6092fb41f ("serial: stm32-usart: Add STM32 USART Driver") Cc: stable Signed-off-by: Erwan Le Ray Signed-off-by: Valentin Caron Link: https://lore.kernel.org/r/20220111164441.6178-3-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/stm32-usart.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -575,7 +575,7 @@ static void stm32_usart_start_tx(struct struct serial_rs485 *rs485conf = &port->rs485; struct circ_buf *xmit = &port->state->xmit; - if (uart_circ_empty(xmit)) + if (uart_circ_empty(xmit) && !port->x_char) return; if (rs485conf->flags & SER_RS485_ENABLED) {