Messages in this thread | | | Date | Wed, 25 Jan 2017 11:02:15 +0000 | From | Peter Griffin <> | Subject | Re: [STLinux Kernel] [PATCH 1/8] serial: st-asc: Ignore the parity error bit if 8-bit mode is enabled |
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On Tue, 24 Jan 2017, Lee Jones wrote:
> The datasheet states: > > "If the MODE field selects an 8-bit frame then this [parity error] bit > is undefined. Software should ignore this bit when reading 8-bit frames." > > Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Peter Griffin <peter.griffin@linaro.org>
> --- > drivers/tty/serial/st-asc.c | 16 +++++++++++++--- > 1 file changed, 13 insertions(+), 3 deletions(-) > > diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c > index 379e5bd..69e6232 100644 > --- a/drivers/tty/serial/st-asc.c > +++ b/drivers/tty/serial/st-asc.c > @@ -287,9 +287,19 @@ static void asc_transmit_chars(struct uart_port *port) > static void asc_receive_chars(struct uart_port *port) > { > struct tty_port *tport = &port->state->port; > - unsigned long status; > + unsigned long status, mode; > unsigned long c = 0; > char flag; > + bool ignore_pe = false; > + > + /* > + * Datasheet states: If the MODE field selects an 8-bit frame then > + * this [parity error] bit is undefined. Software should ignore this > + * bit when reading 8-bit frames. > + */ > + mode = asc_in(port, ASC_CTL) & ASC_CTL_MODE_MSK; > + if (mode == ASC_CTL_MODE_8BIT || mode == ASC_CTL_MODE_8BIT_PAR) > + ignore_pe = true; > > if (port->irq_wake) > pm_wakeup_event(tport->tty->dev, 0); > @@ -299,8 +309,8 @@ static void asc_receive_chars(struct uart_port *port) > flag = TTY_NORMAL; > port->icount.rx++; > > - if ((c & (ASC_RXBUF_FE | ASC_RXBUF_PE)) || > - status & ASC_STA_OE) { > + if (status & ASC_STA_OE || c & ASC_RXBUF_FE || > + (c & ASC_RXBUF_PE && !ignore_pe)) { > > if (c & ASC_RXBUF_FE) { > if (c == (ASC_RXBUF_FE | ASC_RXBUF_DUMMY_RX)) {
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