[STLinux Kernel] [PATCH 1/8] serial: st-asc: Ignore the parity error bit if 8-bit mode is enabled
From: peter.griffin@linaro.org (Peter Griffin)
Date: 2017-01-25 11:02:22
Also in:
linux-devicetree, linux-serial, lkml
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 <redacted>
Acked-by: Peter Griffin <peter.griffin@linaro.org>
quoted hunk ↗ jump to hunk
--- 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)) {