When a break signal is detected, the next character should be ignored.
This was not implemented correctly for the pnx8xxx_uart driver.
[From further discussion:
Correct, you can look to it as two separate bugs:
a) the next character is not ignored while it should;
b) the status bits 31-8 are copied to the 'ch' variable while they shouldn't.
Both bugs prevent correct break signal handling (and therefore correct
behaviour of the magic SysRq key). Bug b didn't cause too much trouble
earlier because in most situations the status bits are all zero; for
this case they unfortunately aren't.
]
Signed-off-by: Mischa Jonker <mischa.jonker@nxp.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/serial/pnx8xxx_uart.c b/drivers/serial/pnx8xxx_uart.c
index 22e30d2..1bb8f1b 100644
--- a/drivers/serial/pnx8xxx_uart.c
+++ b/drivers/serial/pnx8xxx_uart.c
@@ -187,7 +187,7 @@
status = FIFO_TO_SM(serial_in(sport, PNX8XXX_FIFO)) |
ISTAT_TO_SM(serial_in(sport, PNX8XXX_ISTAT));
while (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFIFO)) {
- ch = serial_in(sport, PNX8XXX_FIFO);
+ ch = serial_in(sport, PNX8XXX_FIFO) & 0xff;
sport->port.icount.rx++;
@@ -198,9 +198,16 @@
* out of the main execution path
*/
if (status & (FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE |
- PNX8XXX_UART_FIFO_RXPAR) |
+ PNX8XXX_UART_FIFO_RXPAR |
+ PNX8XXX_UART_FIFO_RXBRK) |
ISTAT_TO_SM(PNX8XXX_UART_INT_RXOVRN))) {
- if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXPAR))
+ if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXBRK)) {
+ status &= ~(FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE) |
+ FIFO_TO_SM(PNX8XXX_UART_FIFO_RXPAR));
+ sport->port.icount.brk++;
+ if (uart_handle_break(&sport->port))
+ goto ignore_char;
+ } else if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXPAR))
sport->port.icount.parity++;
else if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE))
sport->port.icount.frame++;
@@ -284,14 +291,8 @@
/* Get the interrupts */
status = serial_in(sport, PNX8XXX_ISTAT) & serial_in(sport, PNX8XXX_IEN);
- /* Break signal received */
- if (status & PNX8XXX_UART_INT_BREAK) {
- sport->port.icount.brk++;
- uart_handle_break(&sport->port);
- }
-
- /* Byte received */
- if (status & PNX8XXX_UART_INT_RX)
+ /* Byte or break signal received */
+ if (status & (PNX8XXX_UART_INT_RX | PNX8XXX_UART_INT_BREAK))
pnx8xxx_rx_chars(sport);
/* TX holding register empty - transmit a byte */