From mboxrd@z Thu Jan 1 00:00:00 1970 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 57C15C54E94 for ; Sun, 22 Jan 2023 15:19:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231194AbjAVPTB (ORCPT ); Sun, 22 Jan 2023 10:19:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46232 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231190AbjAVPTB (ORCPT ); Sun, 22 Jan 2023 10:19:01 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 38E0B20058 for ; Sun, 22 Jan 2023 07:19:00 -0800 (PST) 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 dfw.source.kernel.org (Postfix) with ESMTPS id C86BC60C44 for ; Sun, 22 Jan 2023 15:18:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DBB3AC4339B; Sun, 22 Jan 2023 15:18:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1674400739; bh=ACUv1GCDZl5dqgNypOm45KYCeJ8uXIUPJlFxYQhnpHk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=k5enB4weqc/iZ2DBbJk1dF4jOScojxOKM1YhxRsGghwmbYeY3PIkEsFy3I7x/jpev 8dLlRTytW795mb4x6sxGKZE5J4bFfQC2n+0AHZ7EKwLgYZOlBgH4DhX3TPknP5EnGE qiuSxNyrrxQ7TCnRZiz0O8GU6ftvpDSlkLqi7/Y0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Lino Sanfilippo Subject: [PATCH 5.15 090/117] serial: amba-pl011: fix high priority character transmission in rs486 mode Date: Sun, 22 Jan 2023 16:04:40 +0100 Message-Id: <20230122150236.542409845@linuxfoundation.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230122150232.736358800@linuxfoundation.org> References: <20230122150232.736358800@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Lino Sanfilippo commit 4f39aca2360c82dccd2f5179d77e94aab665bea6 upstream. In RS485 mode the transmission of a high priority character fails since it is written to the data register before the transmitter is enabled. Fix this in pl011_tx_chars() by enabling RS485 transmission before writing the character. Fixes: 8d479237727c ("serial: amba-pl011: add RS485 support") Cc: stable@vger.kernel.org Signed-off-by: Lino Sanfilippo Link: https://lore.kernel.org/r/20230108181735.10937-1-LinoSanfilippo@gmx.de Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/amba-pl011.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -1472,6 +1472,10 @@ static bool pl011_tx_chars(struct uart_a struct circ_buf *xmit = &uap->port.state->xmit; int count = uap->fifosize >> 1; + if ((uap->port.rs485.flags & SER_RS485_ENABLED) && + !uap->rs485_tx_started) + pl011_rs485_tx_start(uap); + if (uap->port.x_char) { if (!pl011_tx_char(uap, uap->port.x_char, from_irq)) return true; @@ -1483,10 +1487,6 @@ static bool pl011_tx_chars(struct uart_a return false; } - if ((uap->port.rs485.flags & SER_RS485_ENABLED) && - !uap->rs485_tx_started) - pl011_rs485_tx_start(uap); - /* If we are using DMA mode, try to send some characters. */ if (pl011_dma_tx_irq(uap)) return true;