From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752398AbeFAMkw (ORCPT ); Fri, 1 Jun 2018 08:40:52 -0400 Received: from mail.micronovasrl.com ([212.103.203.10]:39130 "EHLO mail.micronovasrl.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752262AbeFAMkp (ORCPT ); Fri, 1 Jun 2018 08:40:45 -0400 Authentication-Results: mail.micronovasrl.com (amavisd-new); dkim=pass reason="pass (just generated, assumed good)" header.d=micronovasrl.com X-Spam-Flag: NO X-Spam-Score: -2.9 From: Giulio Benetti To: Greg Kroah-Hartman Cc: Jiri Slaby , Andy Shevchenko , Kees Cook , Matthias Brugger , Allen Pais , Sean Young , Ed Blake , Stefan Potyra , Philipp Zabel , Joshua Scott , Vignesh R , Rolf Evers-Fischer , Aaron Sierra , Rafael Gago , Joel Stanley , Sean Wang , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, Giulio Benetti Subject: [PATCH 5/8] serial: 8250_dw: treat rpm suspend with -EBUSY if RS485 ON and RTS_AFTER_SEND Date: Fri, 1 Jun 2018 14:40:18 +0200 Message-Id: <20180601124021.102970-6-giulio.benetti@micronovasrl.com> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180601124021.102970-1-giulio.benetti@micronovasrl.com> References: <20180601124021.102970-1-giulio.benetti@micronovasrl.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If rs485 is on and RTS_AFTER_SEND it means that in idle state rts pin must be asserted, othwerwise rs485 transceiver will enter tx state. dw8250 when clocks are stopped keeps rts line de-asserted(high), resulting in keeping rs485 transceiver in tx state when port is idle. Check if rs485 is on with RTS_AFTER_SEND set, if so return -EBUSY in rpm_suspend, Signed-off-by: Giulio Benetti --- drivers/tty/serial/8250/8250_dw.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c index 888280ff5451..6b0ee6dc8ad0 100644 --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -668,6 +668,11 @@ static int dw8250_resume(struct device *dev) static int dw8250_runtime_suspend(struct device *dev) { struct dw8250_data *data = dev_get_drvdata(dev); + struct uart_8250_port *up = serial8250_get_port(data->line); + struct uart_port *p = &up->port; + + if (p->rs485.flags & (SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND)) + return -EBUSY; if (!IS_ERR(data->clk)) clk_disable_unprepare(data->clk); -- 2.17.0