Re: [PATCH] tty: make pl011 serial port driver support 485 mode

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Dec 29, 2020 at 04:56:04PM +0800, zhangqiumiao1@huawei.com wrote:
> From: zhangqiumiao <zhangqiumiao1@huawei.com>
> 
> make pl011 serial port support 485 mode full duplex communication
> 
> Signed-off-by: zhangqiumiao <zhangqiumiao1@huawei.com>

Can you please use your "real name" or one you sign documents with?

> ---
>  drivers/tty/serial/amba-pl011.c | 38 +++++++++++++++++++++++++++++++++
>  1 file changed, 38 insertions(+)
> 
> diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
> index c255476cce28..f6a7fe61e699 100644
> --- a/drivers/tty/serial/amba-pl011.c
> +++ b/drivers/tty/serial/amba-pl011.c
> @@ -44,6 +44,7 @@
> 
>  #include "amba-pl011.h"
> 
> +#define ISEMPTY			1
>  #define UART_NR			14
> 
>  #define SERIAL_AMBA_MAJOR	204
> @@ -1284,14 +1285,33 @@ static inline bool pl011_dma_rx_running(struct uart_amba_port *uap)
>  #define pl011_dma_flush_buffer	NULL
>  #endif
> 
> +static unsigned int pl011_tx_empty(struct uart_port *port);
> +
>  static void pl011_stop_tx(struct uart_port *port)
>  {
> +	unsigned int cr;
> +	unsigned int result;
>  	struct uart_amba_port *uap =
> 
>  	uap->im &= ~UART011_TXIM;
>  	pl011_write(uap->im, uap, REG_IMSC);
>  	pl011_dma_tx_stop(uap);
> +	if (port->rs485.flags & SER_RS485_ENABLEED) {
> +		whiel(1) {

You obviously never built this code :(