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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 1C8DAC43603 for ; Thu, 19 Dec 2019 14:51:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E4FAE206EC for ; Thu, 19 Dec 2019 14:51:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576767073; bh=zdOA0WpGahNtfocWFERrDKk6UCtOuy9GMpkckf4Fwxk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=u00yrfCZf9z5nUe6t9uLoVvZL6hWvzLXaWhEmHBw0W6I3HrkUJprmIzZKnbuOYJyb TT9krnGQLwRvQHPOhkotI5/qy49VTYsrP///9aPYXGiH1IzF6nuveMyiVklZRhaJww VT1HrLpVfglUMR5sj9dmxUZO4fteguvzWF/0CdLk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726836AbfLSOvM (ORCPT ); Thu, 19 Dec 2019 09:51:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:59710 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726759AbfLSOvM (ORCPT ); Thu, 19 Dec 2019 09:51:12 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 02BC72053B; Thu, 19 Dec 2019 14:51:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576767071; bh=zdOA0WpGahNtfocWFERrDKk6UCtOuy9GMpkckf4Fwxk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=AKiLxU0tZ0LfjduRGTpGTGQYS6qKBoQYdU/qVU54+NjF1WWbXvmOjo0iDN7KdmFTe T5G+OLjQ8dOdxIrgffd+zHK2JcCwugosgzuI0H7WJ5fSSRvN63FSN0o+pXCRdlkN5q 87Qqze04V9DtkVA7LXOP+UStiGLhyYMlU7cjjkeM= Date: Thu, 19 Dec 2019 15:51:09 +0100 From: Greg Kroah-Hartman To: Dmitry Safonov , Russell King , linux-serial@vger.kernel.org Cc: Jiri Slaby , linux-kernel@vger.kernel.org, kbuild test robot Subject: [PATCH v2] tty: serial: 21285: stop using the unused[] variable from struct uart_port Message-ID: <20191219145109.GA1962496@kroah.com> References: <20191219082006.GA1001454@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191219082006.GA1001454@kroah.com> Sender: linux-serial-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org Much like the samsung_tty driver (now I know where they copied the idea from), the 21285 uart driver uses 2 bytes from the "unused" array of struct uart_port to keep tx/rx enabled/disabled state. Those fields are going away (they were never really needed in the first place), so fix up the 21285 driver by another horrible hack. Instead of creating a whole structure for just 2 bytes, just use two bits from the private_data pointer instead, as that pointer is never used. The two bits reflect if tx/rx is now enabled/disabled. Astute readers will note that once rx is disabled, nothing ever seems to turn it back on, making one wonder if anyone has ever done this. Reported-by: kbuild test robot Cc: Dmitry Safonov Cc: Russell King Cc: Jiri Slaby Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/21285.c | 55 +++++++++++++++++++++++++++++++------- 1 file changed, 45 insertions(+), 10 deletions(-) v2: use clear_bit(), not set_bit() to actually clear a bit :) diff --git a/drivers/tty/serial/21285.c b/drivers/tty/serial/21285.c index 32b3acf8150a..718e010fcb04 100644 --- a/drivers/tty/serial/21285.c +++ b/drivers/tty/serial/21285.c @@ -41,8 +41,43 @@ static const char serial21285_name[] = "Footbridge UART"; -#define tx_enabled(port) ((port)->unused[0]) -#define rx_enabled(port) ((port)->unused[1]) +/* + * We only need 2 bits of data, so instead of creating a whole structure for + * this, use bits of the private_data pointer of the uart port structure. + */ +#define tx_enabled_bit 0 +#define rx_enabled_bit 1 + +static bool is_enabled(struct uart_port *port, int bit) +{ + unsigned long private_data = (unsigned long)port->private_data; + + if (test_bit(bit, &private_data)) + return true; + return false; +} + +static void enable(struct uart_port *port, int bit) +{ + unsigned long private_data = (unsigned long)port->private_data; + + set_bit(bit, &private_data); +} + +static void disable(struct uart_port *port, int bit) +{ + unsigned long private_data = (unsigned long)port->private_data; + + clear_bit(bit, &private_data); +} + +#define is_tx_enabled(port) is_enabled(port, tx_enabled_bit) +#define tx_enable(port) enable(port, tx_enabled_bit) +#define tx_disable(port) disable(port, tx_enabled_bit) + +#define is_rx_enabled(port) is_enabled(port, rx_enabled_bit) +#define rx_enable(port) enable(port, rx_enabled_bit) +#define rx_disable(port) disable(port, rx_enabled_bit) /* * The documented expression for selecting the divisor is: @@ -57,25 +92,25 @@ static const char serial21285_name[] = "Footbridge UART"; static void serial21285_stop_tx(struct uart_port *port) { - if (tx_enabled(port)) { + if (is_tx_enabled(port)) { disable_irq_nosync(IRQ_CONTX); - tx_enabled(port) = 0; + tx_disable(port); } } static void serial21285_start_tx(struct uart_port *port) { - if (!tx_enabled(port)) { + if (!is_tx_enabled(port)) { enable_irq(IRQ_CONTX); - tx_enabled(port) = 1; + tx_enable(port); } } static void serial21285_stop_rx(struct uart_port *port) { - if (rx_enabled(port)) { + if (is_rx_enabled(port)) { disable_irq_nosync(IRQ_CONRX); - rx_enabled(port) = 0; + rx_disable(port); } } @@ -185,8 +220,8 @@ static int serial21285_startup(struct uart_port *port) { int ret; - tx_enabled(port) = 1; - rx_enabled(port) = 1; + tx_enable(port); + rx_enable(port); ret = request_irq(IRQ_CONRX, serial21285_rx_chars, 0, serial21285_name, port); -- 2.24.1