serial: st-asc: Ignore the parity error bit if 8-bit mode is enabled

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."

Acked-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Lee Jones 2017-02-03 10:23:10 +00:00 committed by Greg Kroah-Hartman
parent 1c9c858e2f
commit 5ab066e546
1 changed files with 13 additions and 3 deletions

View File

@ -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)) {