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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: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Nicolas Ferre 2016-06-17 12:05:46 +02:00 committed by Greg Kroah-Hartman
parent 9b6519009d
commit 9205218e49
1 changed files with 17 additions and 26 deletions
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43
drivers/tty/serial/atmel_serial.c
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@ -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