> -----Original Message----- > From: Thierry Reding <[email protected]> > Sent: Tuesday, August 13, 2019 3:22 PM > To: Krishna Yarlagadda <[email protected]> > Cc: [email protected]; [email protected]; > [email protected]; Jonathan Hunter <[email protected]>; Laxman > Dewangan <[email protected]>; [email protected]; linux- > [email protected]; [email protected]; linux- > [email protected]; [email protected]; Shardar Mohammed > <[email protected]> > 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 <[email protected]> > > Signed-off-by: Krishna Yarlagadda <[email protected]> > > --- > > 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 > >
