diff options
Diffstat (limited to 'drivers/tty/serial/8250/8250_port.c')
| -rw-r--r-- | drivers/tty/serial/8250/8250_port.c | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index fa43df05342b..fe8d79c4ae95 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -15,6 +15,7 @@ #include <linux/moduleparam.h> #include <linux/ioport.h> #include <linux/init.h> +#include <linux/irq.h> #include <linux/console.h> #include <linux/gpio/consumer.h> #include <linux/sysrq.h> @@ -1903,6 +1904,17 @@ EXPORT_SYMBOL_GPL(serial8250_modem_status); static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir) { switch (iir & 0x3f) { + case UART_IIR_THRI: + /* + * Postpone DMA or not decision to IIR_RDI or IIR_RX_TIMEOUT + * because it's impossible to do an informed decision about + * that with IIR_THRI. + * + * This also fixes one known DMA Rx corruption issue where + * DR is asserted but DMA Rx only gets a corrupted zero byte + * (too early DR?). + */ + return false; case UART_IIR_RDI: if (!up->dma->rx_running) break; @@ -1921,6 +1933,7 @@ static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir) int serial8250_handle_irq(struct uart_port *port, unsigned int iir) { struct uart_8250_port *up = up_to_u8250p(port); + struct tty_port *tport = &port->state->port; bool skip_rx = false; unsigned long flags; u16 status; @@ -1946,6 +1959,8 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir) skip_rx = true; if (status & (UART_LSR_DR | UART_LSR_BI) && !skip_rx) { + if (irqd_is_wakeup_set(irq_get_irq_data(port->irq))) + pm_wakeup_event(tport->tty->dev, 0); if (!up->dma || handle_rx_dma(up, iir)) status = serial8250_rx_chars(up, status); } @@ -2005,18 +2020,19 @@ static int serial8250_tx_threshold_handle_irq(struct uart_port *port) static unsigned int serial8250_tx_empty(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); + unsigned int result = 0; unsigned long flags; - u16 lsr; serial8250_rpm_get(up); spin_lock_irqsave(&port->lock, flags); - lsr = serial_lsr_in(up); + if (!serial8250_tx_dma_running(up) && uart_lsr_tx_empty(serial_lsr_in(up))) + result = TIOCSER_TEMT; spin_unlock_irqrestore(&port->lock, flags); serial8250_rpm_put(up); - return uart_lsr_tx_empty(lsr) ? TIOCSER_TEMT : 0; + return result; } unsigned int serial8250_do_get_mctrl(struct uart_port *port) |