From mboxrd@z Thu Jan 1 00:00:00 1970 From: Krishna Yarlagadda Subject: RE: [PATCH 06/14] serial: tegra: report error to upper tty layer Date: Tue, 27 Aug 2019 09:29:44 +0000 Message-ID: References: <1565609303-27000-1-git-send-email-kyarlagadda@nvidia.com> <1565609303-27000-7-git-send-email-kyarlagadda@nvidia.com> <20190813095219.GK1137@ulmo> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20190813095219.GK1137@ulmo> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Thierry Reding Cc: "gregkh@linuxfoundation.org" , "robh+dt@kernel.org" , "mark.rutland@arm.com" , Jonathan Hunter , Laxman Dewangan , "jslaby@suse.com" , "linux-serial@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-tegra@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Shardar Mohammed List-Id: devicetree@vger.kernel.org > -----Original Message----- > From: Thierry Reding > Sent: Tuesday, August 13, 2019 3:22 PM > To: Krishna Yarlagadda > Cc: gregkh@linuxfoundation.org; robh+dt@kernel.org;=20 > mark.rutland@arm.com; Jonathan Hunter ; Laxman=20 > Dewangan ; jslaby@suse.com; linux-=20 > serial@vger.kernel.org; devicetree@vger.kernel.org; linux-=20 > tegra@vger.kernel.org; linux-kernel@vger.kernel.org; Shardar Mohammed=20 > > Subject: Re: [PATCH 06/14] serial: tegra: report error to upper tty=20 > layer >=20 > On Mon, Aug 12, 2019 at 04:58:15PM +0530, Krishna Yarlagadda wrote: > > Report overrun/parity/frame/break errors to top tty layer. Add=20 > > support to ignore break character if IGNBRK is set. > > > > Signed-off-by: Shardar Shariff Md > > Signed-off-by: Krishna Yarlagadda > > --- > > 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 =3D TTY_BREAK; > > + tup->uport.icount.brk++; > > + dev_err(tup->uport.dev, "Got Break\n"); >=20 > I know this is preexisting, but why do we want to output an error=20 > message in these cases. Isn't it perfectly legal for this to happen? >=20 > Thierry >=20 It is valid to have breaks for sysrq requests. But they also indicate possi= ble 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 =3D tegra_uart_decode_rx_error(tup, lsr); > > + if (flag !=3D TTY_NORMAL) > > + continue; > > + > > ch =3D (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) =3D=3D 0) > > tup->uport.ignore_status_mask |=3D UART_LSR_DR; > > + if (termios->c_iflag & IGNBRK) > > + tup->uport.ignore_status_mask |=3D UART_LSR_BI; > > > > spin_unlock_irqrestore(&u->lock, flags); } > > -- > > 2.7.4 > >