From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sascha Hauer Subject: Re: [PATCH] serial/imx: support to handle break character Date: Wed, 24 Aug 2011 17:49:05 +0200 Message-ID: <20110824154905.GE31404@pengutronix.de> References: <1314178907-20074-1-git-send-email-jason77.wang@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from metis.ext.pengutronix.de ([92.198.50.35]:38463 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751655Ab1HXPtH (ORCPT ); Wed, 24 Aug 2011 11:49:07 -0400 Content-Disposition: inline In-Reply-To: <1314178907-20074-1-git-send-email-jason77.wang@gmail.com> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Hui Wang Cc: gregkh@suse.de, alan@linux.intel.com, linux-serial@vger.kernel.org On Wed, Aug 24, 2011 at 05:41:47PM +0800, Hui Wang wrote: > The imx UART hardware controller can identify BREAK character and the > imx_set_termios() can accept BRKINT set by users, but current existing > imx_rxint() can't pass BREAK character and TTY_BREAK to the tty layer > as other serial drivers do (8250.c omap_serial.c). > > Here add code to handle BREAK character and pass it to tty layer. > > To detect error occurrence, i use URXD_ERR to replace (URXD_OVRRUN | > URXD_FRMERR | ...) because any kind of error occurs, URXD_ERR will > always be set to 1. > > I put the URXD_BRK to the first place to check since when BREAK error > occurs, not only URXD_BRK is set to 1, but also URXD_PRERR and > URXD_FRMERR are all set to 1. This arrangement can filter out fake > parity and frame errors when BREAK error occurs. > > Signed-off-by: Hui Wang > Cc: Sascha Hauer > Cc: Alan Cox > Cc: Greg Kroah-Hartman Acked-by: Sascha Hauer > --- > drivers/tty/serial/imx.c | 10 +++++++--- > 1 files changed, 7 insertions(+), 3 deletions(-) > > diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c > index 7e91b3d..54ffdc6 100644 > --- a/drivers/tty/serial/imx.c > +++ b/drivers/tty/serial/imx.c > @@ -508,8 +508,10 @@ static irqreturn_t imx_rxint(int irq, void *dev_id) > if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx)) > continue; > > - if (rx & (URXD_PRERR | URXD_OVRRUN | URXD_FRMERR) ) { > - if (rx & URXD_PRERR) > + if (unlikely(rx & URXD_ERR)) { > + if (rx & URXD_BRK) > + sport->port.icount.brk++; > + else if (rx & URXD_PRERR) > sport->port.icount.parity++; > else if (rx & URXD_FRMERR) > sport->port.icount.frame++; > @@ -524,7 +526,9 @@ static irqreturn_t imx_rxint(int irq, void *dev_id) > > rx &= sport->port.read_status_mask; > > - if (rx & URXD_PRERR) > + if (rx & URXD_BRK) > + flg = TTY_BREAK; > + else if (rx & URXD_PRERR) > flg = TTY_PARITY; > else if (rx & URXD_FRMERR) > flg = TTY_FRAME; > -- > 1.7.6 > > -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |