diff options
| -rw-r--r-- | drivers/tty/serial/atmel_serial.c | 61 |
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); |