From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933521AbdAKTtf (ORCPT ); Wed, 11 Jan 2017 14:49:35 -0500 Received: from mail-pg0-f41.google.com ([74.125.83.41]:33755 "EHLO mail-pg0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933032AbdAKTtd (ORCPT ); Wed, 11 Jan 2017 14:49:33 -0500 From: Jason Uy To: Greg Kroah-Hartman , Jiri Slaby Cc: Andy Shevchenko , Kefeng Wang , Noam Camus , Heikki Krogerus , Wang Hongcheng , Jason Uy , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, bcm-kernel-feedback-list@broadcom.com Subject: [PATCH v2 1/1] serial: 8250_dw: Allow hardware flow control to be used Date: Wed, 11 Jan 2017 11:48:20 -0800 Message-Id: <1484164100-9805-2-git-send-email-jason.uy@broadcom.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1484164100-9805-1-git-send-email-jason.uy@broadcom.com> References: <1484164100-9805-1-git-send-email-jason.uy@broadcom.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In the most common use case, the Synopsys DW UART driver does not set the set_termios callback function. This prevents UPSTAT_AUTOCTS from being set when the UART flag CRTSCTS is set. As a result, the driver will use software flow control as opposed to hardware flow control. To fix the problem, the set_termios callback function is set to the DW specific function. The logic to set UPSTAT_AUTOCTS is moved so that any clock error will not affect setting the hardware flow control. Reviewed-by: Scott Branden Reviewed-by: Ray Jui Signed-off-by: Jason Uy --- drivers/tty/serial/8250/8250_dw.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c index c89fafc..c89ae45 100644 --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -248,11 +248,11 @@ static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios, if (!ret) p->uartclk = rate; +out: p->status &= ~UPSTAT_AUTOCTS; if (termios->c_cflag & CRTSCTS) p->status |= UPSTAT_AUTOCTS; -out: serial8250_do_set_termios(p, termios, old); } @@ -326,13 +326,11 @@ static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data) p->serial_in = dw8250_serial_in32; data->uart_16550_compatible = true; } - p->set_termios = dw8250_set_termios; } /* Platforms with iDMA */ if (platform_get_resource_byname(to_platform_device(p->dev), IORESOURCE_MEM, "lpss_priv")) { - p->set_termios = dw8250_set_termios; data->dma.rx_param = p->dev->parent; data->dma.tx_param = p->dev->parent; data->dma.fn = dw8250_idma_filter; @@ -414,6 +412,7 @@ static int dw8250_probe(struct platform_device *pdev) p->serial_in = dw8250_serial_in; p->serial_out = dw8250_serial_out; p->set_ldisc = dw8250_set_ldisc; + p->set_termios = dw8250_set_termios; p->membase = devm_ioremap(dev, regs->start, resource_size(regs)); if (!p->membase) -- 1.9.1