From patchwork Mon Jan 31 10:55:11 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 538847 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 B6369C433EF for ; Mon, 31 Jan 2022 11:11:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349270AbiAaLLX (ORCPT ); Mon, 31 Jan 2022 06:11:23 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:41462 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1376622AbiAaLIn (ORCPT ); Mon, 31 Jan 2022 06:08:43 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 417D860B28; Mon, 31 Jan 2022 11:08:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 26A02C340E8; Mon, 31 Jan 2022 11:08:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643627322; bh=WIkSwz0/m7xluTgNQRpv2pohUX/lU1/FJ1P7c5Vh3ho=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bSGkh4QPR4OmfKF5zJflRSKPJHD4lURSHX6ghjKAzHNDD6VPPq49J3E9Vz3Wbus/2 dRYecAj0Xci6UWaiOx3TGs2+tnb1QvMXBDrYaRxENRH03Okwj8vpevmFKCJR+YjgEx TW0hy1D4LdtH7PHuDc4WWU3z5TOQX6m0NZFUmTjw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lino Sanfilippo , Jochen Mades , Lukas Wunner Subject: [PATCH 5.15 046/171] serial: pl011: Fix incorrect rs485 RTS polarity on set_mctrl Date: Mon, 31 Jan 2022 11:55:11 +0100 Message-Id: <20220131105231.578810721@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: Jochen Mades commit 62f676ff7898f6c1bd26ce014564773a3dc00601 upstream. Commit 8d479237727c ("serial: amba-pl011: add RS485 support") sought to keep RTS deasserted on set_mctrl if rs485 is enabled. However it did so only if deasserted RTS polarity is high. Fix it in case it's low. Fixes: 8d479237727c ("serial: amba-pl011: add RS485 support") Cc: stable@vger.kernel.org # v5.15+ Cc: Lino Sanfilippo Signed-off-by: Jochen Mades [lukas: copyedit commit message, add stable designation] Signed-off-by: Lukas Wunner Link: https://lore.kernel.org/r/85fa3323ba8c307943969b7343e23f34c3e652ba.1642909284.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/amba-pl011.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -1615,8 +1615,12 @@ static void pl011_set_mctrl(struct uart_ container_of(port, struct uart_amba_port, port); unsigned int cr; - if (port->rs485.flags & SER_RS485_ENABLED) - mctrl &= ~TIOCM_RTS; + if (port->rs485.flags & SER_RS485_ENABLED) { + if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND) + mctrl &= ~TIOCM_RTS; + else + mctrl |= TIOCM_RTS; + } cr = pl011_read(uap, REG_CR);