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Commit 9205218e authored by Nicolas Ferre's avatar Nicolas Ferre Committed by Greg Kroah-Hartman
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tty/serial: atmel: re-integrate status check in irq handler 



The IRQ status check and related actions was done in the tasklet without
benefit. So, move it back to the IRQ context to simplify IRQ handling and
having the possibility to split the tasklet in two separated ones for
receive and transmit actions.

Signed-off-by: default avatarNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: default avatarLudovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 9b651900

drivers/tty/serial/atmel_serial.c

+17 −26
Original line number Diff line number Diff line
@@ -146,9 +146,7 @@ struct atmel_uart_port { 
	struct scatterlist		sg_tx;

	struct scatterlist		sg_rx;

	struct tasklet_struct	tasklet;

	unsigned int		irq_status;

	unsigned int		irq_status_prev;

	unsigned int		status_change;

	unsigned int		tx_len;



	struct circ_buf		rx_ring;
@@ -1237,14 +1235,27 @@ atmel_handle_status(struct uart_port *port, unsigned int pending, 
		    unsigned int status)

{

	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);

	unsigned int status_change;



	if (pending & (ATMEL_US_RIIC | ATMEL_US_DSRIC | ATMEL_US_DCDIC

				| ATMEL_US_CTSIC)) {

		atmel_port->irq_status = status;

		atmel_port->status_change = atmel_port->irq_status ^

					    atmel_port->irq_status_prev;

		status_change = status ^ atmel_port->irq_status_prev;

		atmel_port->irq_status_prev = status;

		tasklet_schedule(&atmel_port->tasklet);



		if (status_change & (ATMEL_US_RI | ATMEL_US_DSR

					| ATMEL_US_DCD | ATMEL_US_CTS)) {

			/* TODO: All reads to CSR will clear these interrupts! */

			if (status_change & ATMEL_US_RI)

				port->icount.rng++;

			if (status_change & ATMEL_US_DSR)

				port->icount.dsr++;

			if (status_change & ATMEL_US_DCD)

				uart_handle_dcd_change(port, !(status & ATMEL_US_DCD));

			if (status_change & ATMEL_US_CTS)

				uart_handle_cts_change(port, !(status & ATMEL_US_CTS));



			wake_up_interruptible(&port->state->port.delta_msr_wait);

		}

	}

}
@@ -1575,31 +1586,12 @@ static void atmel_tasklet_func(unsigned long data) 
{

	struct uart_port *port = (struct uart_port *)data;

	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);

	unsigned int status = atmel_port->irq_status;

	unsigned int status_change = atmel_port->status_change;



	/* The interrupt handler does not take the lock */

	spin_lock(&port->lock);



	atmel_port->schedule_tx(port);



	if (status_change & (ATMEL_US_RI | ATMEL_US_DSR

				| ATMEL_US_DCD | ATMEL_US_CTS)) {

		/* TODO: All reads to CSR will clear these interrupts! */

		if (status_change & ATMEL_US_RI)

			port->icount.rng++;

		if (status_change & ATMEL_US_DSR)

			port->icount.dsr++;

		if (status_change & ATMEL_US_DCD)

			uart_handle_dcd_change(port, !(status & ATMEL_US_DCD));

		if (status_change & ATMEL_US_CTS)

			uart_handle_cts_change(port, !(status & ATMEL_US_CTS));



		wake_up_interruptible(&port->state->port.delta_msr_wait);



		atmel_port->status_change = 0;

	}



	atmel_port->schedule_rx(port);



	spin_unlock(&port->lock);
@@ -1833,7 +1825,6 @@ static int atmel_startup(struct uart_port *port) 


	/* Save current CSR for comparison in atmel_tasklet_func() */

	atmel_port->irq_status_prev = atmel_get_lines_status(port);

	atmel_port->irq_status = atmel_port->irq_status_prev;



	/*

	 * Finally, enable the serial port