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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>
hifive-unleashed-5.1
Mischa Jonker 2009-01-15 13:30:56 +00:00 committed by Linus Torvalds
parent 7fdd4f76e9
commit cd1e40f098
1 changed files with 12 additions and 11 deletions
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23
drivers/serial/pnx8xxx_uart.c
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@ -187,7 +187,7 @@ static void pnx8xxx_rx_chars(struct pnx8xxx_port *sport)
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 @@ static void pnx8xxx_rx_chars(struct pnx8xxx_port *sport)
* 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 @@ static irqreturn_t pnx8xxx_int(int irq, void *dev_id)
/* 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 */