From cd1e40f0981e22018373307cd4087dc876b08fb0 Mon Sep 17 00:00:00 2001 From: Mischa Jonker Date: Thu, 15 Jan 2009 13:30:56 +0000 Subject: [PATCH 1/1] 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 Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- drivers/serial/pnx8xxx_uart.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) 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 @@ 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 */ -- 1.8.2.3