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

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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
1 changed files with 16 additions and 10 deletions
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26
drivers/tty/serial/arc_uart.c
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@ -209,9 +209,9 @@ static void arc_serial_start_tx(struct uart_port *port)
arc_serial_tx_chars(uart); 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 * 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 * before RX-EMPTY=0, implies some sort of buffering going on in the
* controller, which is indeed the Rx-FIFO. * controller, which is indeed the Rx-FIFO.
*/ */
while (!((status = UART_GET_STATUS(uart)) & RXEMPTY)) { do {
/*
ch = UART_GET_DATA(uart); * This could be an Rx Intr for err (no data),
uart->port.icount.rx++; * so check err and clear that Intr first
*/
if (unlikely(status & (RXOERR | RXFERR))) { if (unlikely(status & (RXOERR | RXFERR))) {
if (status & RXOERR) { if (status & RXOERR) {
uart->port.icount.overrun++; uart->port.icount.overrun++;
@ -242,6 +242,12 @@ static void arc_serial_rx_chars(struct arc_uart_port *uart)
} else } else
flg = TTY_NORMAL; 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))) if (unlikely(uart_handle_sysrq_char(&uart->port, ch)))
goto done; goto done;
@ -249,7 +255,7 @@ static void arc_serial_rx_chars(struct arc_uart_port *uart)
done: done:
tty_flip_buffer_push(&uart->port.state->port); 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. * notifications from the UART Controller.
* To demultiplex between the two, we check the relevant bits * 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 */ /* already in ISR, no need of xx_irqsave */
spin_lock(&uart->port.lock); spin_lock(&uart->port.lock);
arc_serial_rx_chars(uart); arc_serial_rx_chars(uart, status);
spin_unlock(&uart->port.lock); spin_unlock(&uart->port.lock);
} }