diff options
| -rw-r--r-- | drivers/tty/serial/qcom_geni_serial.c | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index 8fead2e27eb9..cf7a95e339ad 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -722,6 +722,7 @@ static void qcom_geni_serial_handle_tx(struct uart_port *uport, bool done, size_t pending; int i; u32 status; + u32 irq_en; unsigned int chunk; int tail; @@ -750,6 +751,11 @@ static void qcom_geni_serial_handle_tx(struct uart_port *uport, bool done, if (!port->tx_remaining) { qcom_geni_serial_setup_tx(uport, pending); port->tx_remaining = pending; + + irq_en = readl_relaxed(uport->membase + SE_GENI_M_IRQ_EN); + if (!(irq_en & M_TX_FIFO_WATERMARK_EN)) + writel_relaxed(irq_en | M_TX_FIFO_WATERMARK_EN, + uport->membase + SE_GENI_M_IRQ_EN); } remaining = chunk; @@ -773,7 +779,23 @@ static void qcom_geni_serial_handle_tx(struct uart_port *uport, bool done, } xmit->tail = tail & (UART_XMIT_SIZE - 1); + + /* + * The tx fifo watermark is level triggered and latched. Though we had + * cleared it in qcom_geni_serial_isr it will have already reasserted + * so we must clear it again here after our writes. + */ + writel_relaxed(M_TX_FIFO_WATERMARK_EN, + uport->membase + SE_GENI_M_IRQ_CLEAR); + out_write_wakeup: + if (!port->tx_remaining) { + irq_en = readl_relaxed(uport->membase + SE_GENI_M_IRQ_EN); + if (irq_en & M_TX_FIFO_WATERMARK_EN) + writel_relaxed(irq_en & ~M_TX_FIFO_WATERMARK_EN, + uport->membase + SE_GENI_M_IRQ_EN); + } + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(uport); } @@ -809,8 +831,7 @@ static irqreturn_t qcom_geni_serial_isr(int isr, void *dev) tty_insert_flip_char(tport, 0, TTY_OVERRUN); } - if (m_irq_status & (M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN) && - m_irq_en & (M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN)) + if (m_irq_status & m_irq_en & (M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN)) qcom_geni_serial_handle_tx(uport, m_irq_status & M_CMD_DONE_EN, geni_status & M_GENI_CMD_ACTIVE); |