From: Krishna Yarlagadda <kyarlagadda@nvidia.com>
To: Thierry Reding <thierry.reding@gmail.com>
Cc: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
"robh+dt@kernel.org" <robh+dt@kernel.org>,
"mark.rutland@arm.com" <mark.rutland@arm.com>,
Jonathan Hunter <jonathanh@nvidia.com>,
"Laxman Dewangan" <ldewangan@nvidia.com>,
"jslaby@suse.com" <jslaby@suse.com>,
"linux-serial@vger.kernel.org" <linux-serial@vger.kernel.org>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"linux-tegra@vger.kernel.org" <linux-tegra@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Shardar Mohammed" <smohammed@nvidia.com>
Subject: RE: [PATCH 06/14] serial: tegra: report error to upper tty layer
Date: Tue, 27 Aug 2019 09:29:44 +0000 [thread overview]
Message-ID: <SN6PR12MB273439430F80C358B6DB663DC3A00@SN6PR12MB2734.namprd12.prod.outlook.com> (raw)
In-Reply-To: <20190813095219.GK1137@ulmo>
> -----Original Message-----
> From: Thierry Reding <thierry.reding@gmail.com>
> Sent: Tuesday, August 13, 2019 3:22 PM
> To: Krishna Yarlagadda <kyarlagadda@nvidia.com>
> Cc: gregkh@linuxfoundation.org; robh+dt@kernel.org;
> mark.rutland@arm.com; Jonathan Hunter <jonathanh@nvidia.com>; Laxman
> Dewangan <ldewangan@nvidia.com>; jslaby@suse.com; linux-
> serial@vger.kernel.org; devicetree@vger.kernel.org; linux-
> tegra@vger.kernel.org; linux-kernel@vger.kernel.org; Shardar Mohammed
> <smohammed@nvidia.com>
> Subject: Re: [PATCH 06/14] serial: tegra: report error to upper tty
> layer
>
> On Mon, Aug 12, 2019 at 04:58:15PM +0530, Krishna Yarlagadda wrote:
> > Report overrun/parity/frame/break errors to top tty layer. Add
> > support to ignore break character if IGNBRK is set.
> >
> > Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com>
> > Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
> > ---
> > drivers/tty/serial/serial-tegra.c | 19 ++++++++++++++++---
> > 1 file changed, 16 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/tty/serial/serial-tegra.c
> > b/drivers/tty/serial/serial-tegra.c
> > index f6a3f4e..7ab81bb 100644
> > --- a/drivers/tty/serial/serial-tegra.c
> > +++ b/drivers/tty/serial/serial-tegra.c
> > @@ -374,13 +374,21 @@ static char tegra_uart_decode_rx_error(struct
> tegra_uart_port *tup,
> > tup->uport.icount.frame++;
> > dev_err(tup->uport.dev, "Got frame errors\n");
> > } else if (lsr & UART_LSR_BI) {
> > - dev_err(tup->uport.dev, "Got Break\n");
> > - tup->uport.icount.brk++;
> > - /* If FIFO read error without any data, reset Rx FIFO
> */
> > + /*
> > + * Break error
> > + * If FIFO read error without any data, reset Rx FIFO
> > + */
> > if (!(lsr & UART_LSR_DR) && (lsr & UART_LSR_FIFOE))
> > tegra_uart_fifo_reset(tup,
> UART_FCR_CLEAR_RCVR);
> > + if (tup->uport.ignore_status_mask & UART_LSR_BI)
> > + return TTY_BREAK;
> > + flag = TTY_BREAK;
> > + tup->uport.icount.brk++;
> > + dev_err(tup->uport.dev, "Got Break\n");
>
> I know this is preexisting, but why do we want to output an error
> message in these cases. Isn't it perfectly legal for this to happen?
>
> Thierry
>
It is valid to have breaks for sysrq requests. But they also indicate possible mismatch in baud rate. So warning user as this could be potential issue. I will change this to dev_dbg to avoid spamming user in valid cases.
KY
> > }
> > + uart_insert_char(&tup->uport, lsr, UART_LSR_OE, 0, flag);
> > }
> > +
> > return flag;
> > }
> >
> > @@ -562,6 +570,9 @@ static void tegra_uart_handle_rx_pio(struct
> tegra_uart_port *tup,
> > break;
> >
> > flag = tegra_uart_decode_rx_error(tup, lsr);
> > + if (flag != TTY_NORMAL)
> > + continue;
> > +
> > ch = (unsigned char) tegra_uart_read(tup, UART_RX);
> > tup->uport.icount.rx++;
> >
> > @@ -1224,6 +1235,8 @@ static void tegra_uart_set_termios(struct
> uart_port *u,
> > /* Ignore all characters if CREAD is not set */
> > if ((termios->c_cflag & CREAD) == 0)
> > tup->uport.ignore_status_mask |= UART_LSR_DR;
> > + if (termios->c_iflag & IGNBRK)
> > + tup->uport.ignore_status_mask |= UART_LSR_BI;
> >
> > spin_unlock_irqrestore(&u->lock, flags); }
> > --
> > 2.7.4
> >
next prev parent reply other threads:[~2019-08-27 9:34 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-12 11:28 [PATCH 00/14] serial: tegra: Tegra186 support and fixes Krishna Yarlagadda
2019-08-12 11:28 ` [PATCH 01/14] serial: tegra: add internal loopback functionality Krishna Yarlagadda
2019-08-13 9:38 ` Thierry Reding
2019-08-12 11:28 ` [PATCH 02/14] serial: tegra: add support to ignore read Krishna Yarlagadda
2019-08-13 9:42 ` Thierry Reding
2019-08-27 9:29 ` Krishna Yarlagadda
2019-08-12 11:28 ` [PATCH 03/14] serial: tegra: avoid reg access when clk disabled Krishna Yarlagadda
2019-08-13 9:45 ` Thierry Reding
2019-08-27 9:29 ` Krishna Yarlagadda
2019-08-12 11:28 ` [PATCH 04/14] serial: tegra: protect IER against LCR.DLAB Krishna Yarlagadda
2019-08-13 9:46 ` Thierry Reding
2019-08-12 11:28 ` [PATCH 05/14] serial: tegra: flush the RX fifo on frame error Krishna Yarlagadda
2019-08-13 9:48 ` Thierry Reding
2019-08-27 9:29 ` Krishna Yarlagadda
2019-08-12 11:28 ` [PATCH 06/14] serial: tegra: report error to upper tty layer Krishna Yarlagadda
2019-08-13 9:52 ` Thierry Reding
2019-08-27 9:29 ` Krishna Yarlagadda [this message]
2019-08-12 11:28 ` [PATCH 07/14] serial: tegra: add compatible for new chips Krishna Yarlagadda
2019-08-13 9:55 ` Thierry Reding
2019-08-27 9:29 ` Krishna Yarlagadda
2019-08-12 11:28 ` [PATCH 08/14] serial: tegra: check for FIFO mode enabled status Krishna Yarlagadda
2019-08-13 10:03 ` Thierry Reding
2019-08-27 9:29 ` Krishna Yarlagadda
2019-08-12 11:28 ` [PATCH 09/14] serial: tegra: set maximum num of uart ports to 8 Krishna Yarlagadda
2019-08-13 10:19 ` Thierry Reding
2019-08-27 9:30 ` Krishna Yarlagadda
2019-08-12 11:28 ` [PATCH 10/14] serial: tegra: add support to use 8 bytes trigger Krishna Yarlagadda
2019-08-19 20:29 ` Jon Hunter
2019-08-27 9:31 ` Krishna Yarlagadda
2019-08-12 11:28 ` [PATCH 11/14] serial: tegra: DT for Adjusted baud rates Krishna Yarlagadda
2019-08-13 10:24 ` Thierry Reding
2019-08-27 9:31 ` Krishna Yarlagadda
2019-08-12 11:28 ` [PATCH 12/14] serial: tegra: add support to adjust baud rate Krishna Yarlagadda
2019-08-12 11:28 ` [PATCH 13/14] serial: tegra: report clk rate errors Krishna Yarlagadda
2019-08-12 11:28 ` [PATCH 14/14] serial: tegra: Add PIO mode support Krishna Yarlagadda
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=SN6PR12MB273439430F80C358B6DB663DC3A00@SN6PR12MB2734.namprd12.prod.outlook.com \
--to=kyarlagadda@nvidia.com \
--cc=devicetree@vger.kernel.org \
--cc=gregkh@linuxfoundation.org \
--cc=jonathanh@nvidia.com \
--cc=jslaby@suse.com \
--cc=ldewangan@nvidia.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-serial@vger.kernel.org \
--cc=linux-tegra@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=robh+dt@kernel.org \
--cc=smohammed@nvidia.com \
--cc=thierry.reding@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).