From mboxrd@z Thu Jan 1 00:00:00 1970 From: Huang Shijie Subject: Re: [PATCH] mxs: uart: allow setting RTS from software Date: Thu, 13 Dec 2012 10:20:27 +0800 Message-ID: <50C93B6B.7090206@freescale.com> References: <1355329913-27666-1-git-send-email-s.trumtrar@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=GB2312 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1355329913-27666-1-git-send-email-s.trumtrar@pengutronix.de> Sender: stable-owner@vger.kernel.org To: Steffen Trumtrar Cc: linux-serial@vger.kernel.org, stable@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Alan Cox List-Id: linux-serial@vger.kernel.org =D3=DA 2012=C4=EA12=D4=C213=C8=D5 00:31, Steffen Trumtrar =D0=B4=B5=C0: > With the patch "serial: mxs-auart: fix the wrong RTS hardware flow co= ntrol" the > mainline mxs-uart driver now sets RTSEN only when hardware flow contr= ol is > enabled via software. It is not possible any longer to set RTS manual= ly via > software. However, the manual modification is a valid operation. > Regain the possibility to set RTS via software and only set RTSEN whe= n hardware Is there any user case to set the RTS via software? I am confused at this. > flow control is explicitly enabled via settermios cflag CRTSCTS. > > Signed-off-by: Steffen Trumtrar > --- > drivers/tty/serial/mxs-auart.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-= auart.c > index 6db23b0..9b62c4b 100644 > --- a/drivers/tty/serial/mxs-auart.c > +++ b/drivers/tty/serial/mxs-auart.c > @@ -412,10 +412,12 @@ static void mxs_auart_set_mctrl(struct uart_por= t *u, unsigned mctrl) > =20 > u32 ctrl =3D readl(u->membase + AUART_CTRL2); > =20 > - ctrl &=3D ~AUART_CTRL2_RTSEN; > + ctrl &=3D ~(AUART_CTRL2_RTSEN | AUART_CTRL2_RTS); > if (mctrl & TIOCM_RTS) { > if (tty_port_cts_enabled(&u->state->port)) > ctrl |=3D AUART_CTRL2_RTSEN; > + else > + ctrl |=3D AUART_CTRL2_RTS; > } > =20 > s->ctrl =3D mctrl; > @@ -678,6 +680,10 @@ static void mxs_auart_settermios(struct uart_por= t *u, > } > ctrl2 |=3D AUART_CTRL2_CTSEN | AUART_CTRL2_RTSEN; > } else { > + u->flags |=3D ASYNC_CTS_FLOW; > + ctrl2 |=3D AUART_CTRL2_CTSEN | AUART_CTRL2_RTSEN; > + } else { > + u->flags &=3D ~ASYNC_CTS_FLOW; bug. Your code adds TWO "else" here. thanks Huang Shijie > ctrl2 &=3D ~(AUART_CTRL2_CTSEN | AUART_CTRL2_RTSEN); > } > =20 From mboxrd@z Thu Jan 1 00:00:00 1970 From: b32955@freescale.com (Huang Shijie) Date: Thu, 13 Dec 2012 10:20:27 +0800 Subject: [PATCH] mxs: uart: allow setting RTS from software In-Reply-To: <1355329913-27666-1-git-send-email-s.trumtrar@pengutronix.de> References: <1355329913-27666-1-git-send-email-s.trumtrar@pengutronix.de> Message-ID: <50C93B6B.7090206@freescale.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org ? 2012?12?13? 00:31, Steffen Trumtrar ??: > With the patch "serial: mxs-auart: fix the wrong RTS hardware flow control" the > mainline mxs-uart driver now sets RTSEN only when hardware flow control is > enabled via software. It is not possible any longer to set RTS manually via > software. However, the manual modification is a valid operation. > Regain the possibility to set RTS via software and only set RTSEN when hardware Is there any user case to set the RTS via software? I am confused at this. > flow control is explicitly enabled via settermios cflag CRTSCTS. > > Signed-off-by: Steffen Trumtrar > --- > drivers/tty/serial/mxs-auart.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c > index 6db23b0..9b62c4b 100644 > --- a/drivers/tty/serial/mxs-auart.c > +++ b/drivers/tty/serial/mxs-auart.c > @@ -412,10 +412,12 @@ static void mxs_auart_set_mctrl(struct uart_port *u, unsigned mctrl) > > u32 ctrl = readl(u->membase + AUART_CTRL2); > > - ctrl &= ~AUART_CTRL2_RTSEN; > + ctrl &= ~(AUART_CTRL2_RTSEN | AUART_CTRL2_RTS); > if (mctrl & TIOCM_RTS) { > if (tty_port_cts_enabled(&u->state->port)) > ctrl |= AUART_CTRL2_RTSEN; > + else > + ctrl |= AUART_CTRL2_RTS; > } > > s->ctrl = mctrl; > @@ -678,6 +680,10 @@ static void mxs_auart_settermios(struct uart_port *u, > } > ctrl2 |= AUART_CTRL2_CTSEN | AUART_CTRL2_RTSEN; > } else { > + u->flags |= ASYNC_CTS_FLOW; > + ctrl2 |= AUART_CTRL2_CTSEN | AUART_CTRL2_RTSEN; > + } else { > + u->flags &= ~ASYNC_CTS_FLOW; bug. Your code adds TWO "else" here. thanks Huang Shijie > ctrl2 &= ~(AUART_CTRL2_CTSEN | AUART_CTRL2_RTSEN); > } >