serial/arc-uart: Handle Rx Error Interrupts w/o any data

Currently, Rx error handling only triggers if there is some Rx data.
Fix that by checking for error - before the data handling.

Reported-by: Mischa Jonker <mjonker@synopsys.com>
Tested-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Vineet Gupta 2013-08-01 21:49:19 -07:00 committed by Greg Kroah-Hartman
parent cb50e5235b
commit 5284eba7b3

View File

@ -209,9 +209,9 @@ static void arc_serial_start_tx(struct uart_port *port)
arc_serial_tx_chars(uart);
}
static void arc_serial_rx_chars(struct arc_uart_port *uart)
static void arc_serial_rx_chars(struct arc_uart_port *uart, unsigned int status)
{
unsigned int status, ch, flg = 0;
unsigned int ch, flg = 0;
/*
* UART has 4 deep RX-FIFO. Driver's recongnition of this fact
@ -222,11 +222,11 @@ static void arc_serial_rx_chars(struct arc_uart_port *uart)
* before RX-EMPTY=0, implies some sort of buffering going on in the
* controller, which is indeed the Rx-FIFO.
*/
while (!((status = UART_GET_STATUS(uart)) & RXEMPTY)) {
ch = UART_GET_DATA(uart);
uart->port.icount.rx++;
do {
/*
* This could be an Rx Intr for err (no data),
* so check err and clear that Intr first
*/
if (unlikely(status & (RXOERR | RXFERR))) {
if (status & RXOERR) {
uart->port.icount.overrun++;
@ -242,6 +242,12 @@ static void arc_serial_rx_chars(struct arc_uart_port *uart)
} else
flg = TTY_NORMAL;
if (status & RXEMPTY)
continue;
ch = UART_GET_DATA(uart);
uart->port.icount.rx++;
if (unlikely(uart_handle_sysrq_char(&uart->port, ch)))
goto done;
@ -249,7 +255,7 @@ static void arc_serial_rx_chars(struct arc_uart_port *uart)
done:
tty_flip_buffer_push(&uart->port.state->port);
}
} while (!((status = UART_GET_STATUS(uart)) & RXEMPTY));
}
/*
@ -292,11 +298,11 @@ static irqreturn_t arc_serial_isr(int irq, void *dev_id)
* notifications from the UART Controller.
* To demultiplex between the two, we check the relevant bits
*/
if ((status & RXIENB) && !(status & RXEMPTY)) {
if (status & RXIENB) {
/* already in ISR, no need of xx_irqsave */
spin_lock(&uart->port.lock);
arc_serial_rx_chars(uart);
arc_serial_rx_chars(uart, status);
spin_unlock(&uart->port.lock);
}