From: Bich Hemon <bich.hemon@xxxxxx> When stm32 dma is used, Data register has to be read in order to clear the RXNE interrupt in case we received data before usart probe. Signed-off-by: Bich Hemon <bich.hemon@xxxxxx> --- drivers/tty/serial/stm32-usart.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index 06a92c8..b1f3aab 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -568,9 +568,18 @@ static int stm32_startup(struct uart_port *port) struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; struct stm32_usart_config *cfg = &stm32_port->info->cfg; const char *name = to_platform_device(port->dev)->name; - u32 val; + u32 val, sr, dr; int ret; + sr = readl_relaxed(port->membase + ofs->isr); + + if ((sr & USART_SR_RXNE) && (stm32_port->rx_ch)) + ret = readl_relaxed_poll_timeout_atomic(port->membase + + ofs->rdr, + dr, + !(sr & USART_SR_RXNE), + 10, 100000); + ret = request_threaded_irq(port->irq, stm32_interrupt, stm32_threaded_interrupt, IRQF_NO_SUSPEND, name, port); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
