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-rw-r--r--drivers/tty/serial/atmel_serial.c61
1 files changed, 38 insertions, 23 deletions
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index f887c1df23e6..2eaa18ddef61 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -153,6 +153,7 @@ struct atmel_uart_port {
struct scatterlist sg_rx;
struct tasklet_struct tasklet_rx;
struct tasklet_struct tasklet_tx;
+ atomic_t tasklet_shutdown;
unsigned int irq_status_prev;
unsigned int tx_len;
@@ -286,6 +287,13 @@ static bool atmel_use_fifo(struct uart_port *port)
return atmel_port->fifo_size;
}
+static void atmel_tasklet_schedule(struct atmel_uart_port *atmel_port,
+ struct tasklet_struct *t)
+{
+ if (!atomic_read(&atmel_port->tasklet_shutdown))
+ tasklet_schedule(t);
+}
+
static unsigned int atmel_get_lines_status(struct uart_port *port)
{
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
@@ -717,7 +725,7 @@ static void atmel_rx_chars(struct uart_port *port)
status = atmel_uart_readl(port, ATMEL_US_CSR);
}
- tasklet_schedule(&atmel_port->tasklet_rx);
+ atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_rx);
}
/*
@@ -788,7 +796,7 @@ static void atmel_complete_tx_dma(void *arg)
* remaining data from the beginning of xmit->buf to xmit->head.
*/
if (!uart_circ_empty(xmit))
- tasklet_schedule(&atmel_port->tasklet_tx);
+ atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_tx);
spin_unlock_irqrestore(&port->lock, flags);
}
@@ -973,7 +981,7 @@ static void atmel_complete_rx_dma(void *arg)
struct uart_port *port = arg;
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
- tasklet_schedule(&atmel_port->tasklet_rx);
+ atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_rx);
}
static void atmel_release_rx_dma(struct uart_port *port)
@@ -1013,7 +1021,7 @@ static void atmel_rx_from_dma(struct uart_port *port)
if (dmastat == DMA_ERROR) {
dev_dbg(port->dev, "Get residue error, restart tasklet\n");
atmel_uart_writel(port, ATMEL_US_IER, ATMEL_US_TIMEOUT);
- tasklet_schedule(&atmel_port->tasklet_rx);
+ atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_rx);
return;
}
@@ -1167,8 +1175,11 @@ static void atmel_uart_timer_callback(unsigned long data)
struct uart_port *port = (void *)data;
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
- tasklet_schedule(&atmel_port->tasklet_rx);
- mod_timer(&atmel_port->uart_timer, jiffies + uart_poll_timeout(port));
+ if (!atomic_read(&atmel_port->tasklet_shutdown)) {
+ tasklet_schedule(&atmel_port->tasklet_rx);
+ mod_timer(&atmel_port->uart_timer,
+ jiffies + uart_poll_timeout(port));
+ }
}
/*
@@ -1190,7 +1201,8 @@ atmel_handle_receive(struct uart_port *port, unsigned int pending)
if (pending & (ATMEL_US_ENDRX | ATMEL_US_TIMEOUT)) {
atmel_uart_writel(port, ATMEL_US_IDR,
(ATMEL_US_ENDRX | ATMEL_US_TIMEOUT));
- tasklet_schedule(&atmel_port->tasklet_rx);
+ atmel_tasklet_schedule(atmel_port,
+ &atmel_port->tasklet_rx);
}
if (pending & (ATMEL_US_RXBRK | ATMEL_US_OVRE |
@@ -1202,7 +1214,8 @@ atmel_handle_receive(struct uart_port *port, unsigned int pending)
if (pending & ATMEL_US_TIMEOUT) {
atmel_uart_writel(port, ATMEL_US_IDR,
ATMEL_US_TIMEOUT);
- tasklet_schedule(&atmel_port->tasklet_rx);
+ atmel_tasklet_schedule(atmel_port,
+ &atmel_port->tasklet_rx);
}
}
@@ -1232,7 +1245,7 @@ atmel_handle_transmit(struct uart_port *port, unsigned int pending)
/* Either PDC or interrupt transmission */
atmel_uart_writel(port, ATMEL_US_IDR,
atmel_port->tx_done_mask);
- tasklet_schedule(&atmel_port->tasklet_tx);
+ atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_tx);
}
}
@@ -1793,8 +1806,11 @@ static int atmel_startup(struct uart_port *port)
return retval;
}
- tasklet_enable(&atmel_port->tasklet_rx);
- tasklet_enable(&atmel_port->tasklet_tx);
+ atomic_set(&atmel_port->tasklet_shutdown, 0);
+ tasklet_init(&atmel_port->tasklet_rx, atmel_tasklet_rx_func,
+ (unsigned long)port);
+ tasklet_init(&atmel_port->tasklet_tx, atmel_tasklet_tx_func,
+ (unsigned long)port);
/*
* Initialize DMA (if necessary)
@@ -1913,31 +1929,36 @@ static void atmel_shutdown(struct uart_port *port)
{
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+ /* Disable interrupts at device level */
+ atmel_uart_writel(port, ATMEL_US_IDR, -1);
+
+ /* Prevent spurious interrupts from scheduling the tasklet */
+ atomic_inc(&atmel_port->tasklet_shutdown);
+
/*
* Prevent any tasklets being scheduled during
* cleanup
*/
del_timer_sync(&atmel_port->uart_timer);
+ /* Make sure that no interrupt is on the fly */
+ synchronize_irq(port->irq);
+
/*
* Clear out any scheduled tasklets before
* we destroy the buffers
*/
- tasklet_disable(&atmel_port->tasklet_rx);
- tasklet_disable(&atmel_port->tasklet_tx);
tasklet_kill(&atmel_port->tasklet_rx);
tasklet_kill(&atmel_port->tasklet_tx);
/*
* Ensure everything is stopped and
- * disable all interrupts, port and break condition.
+ * disable port and break condition.
*/
atmel_stop_rx(port);
atmel_stop_tx(port);
atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA);
- atmel_uart_writel(port, ATMEL_US_IDR, -1);
-
/*
* Shut-down the DMA.
@@ -2321,13 +2342,6 @@ static int atmel_init_port(struct atmel_uart_port *atmel_port,
port->irq = pdev->resource[1].start;
port->rs485_config = atmel_config_rs485;
- tasklet_init(&atmel_port->tasklet_rx, atmel_tasklet_rx_func,
- (unsigned long)port);
- tasklet_init(&atmel_port->tasklet_tx, atmel_tasklet_tx_func,
- (unsigned long)port);
- tasklet_disable(&atmel_port->tasklet_rx);
- tasklet_disable(&atmel_port->tasklet_tx);
-
memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring));
if (pdata && pdata->regs) {
@@ -2712,6 +2726,7 @@ static int atmel_serial_probe(struct platform_device *pdev)
atmel_port->uart.line = ret;
atmel_serial_probe_fifos(atmel_port, pdev);
+ atomic_set(&atmel_port->tasklet_shutdown, 0);
spin_lock_init(&atmel_port->lock_suspended);
ret = atmel_init_port(atmel_port, pdev);