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Commit 5284eba7 authored by Vineet Gupta's avatar Vineet Gupta Committed by Greg Kroah-Hartman
Browse files

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: default avatarMischa Jonker <mjonker@synopsys.com>
Tested-by: default avatarMischa Jonker <mjonker@synopsys.com>
Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent cb50e523

drivers/tty/serial/arc_uart.c

+16 −10
Original line number Diff line number Diff line
@@ -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);

	}