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Commit a9977620 authored by Johannes Thumshirn's avatar Johannes Thumshirn Committed by Greg Kroah-Hartman
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tty: serial: men_z135_uart: Wakeup UART after transmitting 



Call uart_write_wakeup() after writing the hardware FIFO and updateing the FIFO
pointers.

This fixes high latency and jitter on PPP over Serial links.

Reported-by: default avatarJun Shih <Jun.Shih@pason.com>
Tested-by: default avatarJun Shih <Jun.Shih@pason.com>
Signed-off-by: default avatarJohannes Thumshirn <johannes.thumshirn@men.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 8b152f10

drivers/tty/serial/men_z135_uart.c

+3 −3
Original line number Diff line number Diff line
@@ -308,9 +308,6 @@ static void men_z135_handle_tx(struct men_z135_port *uart) 
	if (port->x_char)

		goto out;



	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)

		uart_write_wakeup(port);



	/* calculate bytes to copy */

	qlen = uart_circ_chars_pending(xmit);

	if (qlen <= 0)
@@ -357,6 +354,9 @@ static void men_z135_handle_tx(struct men_z135_port *uart) 


	port->icount.tx += n;



	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)

		uart_write_wakeup(port);



irq_en:

	if (!uart_circ_empty(xmit))

		men_z135_reg_set(uart, MEN_Z135_CONF_REG, MEN_Z135_IER_TXCIEN);