On Sun, 16 Dec 2018 at 19:24, Paul Burton [off-list ref] wrote:

Hi Ezequiel,

On Sun, Dec 16, 2018 at 06:52:53PM -0300, Ezequiel Garcia wrote:

quoted

diff --git a/drivers/tty/serial/8250/8250_port.c

b/drivers/tty/serial/8250/8250_port.c
index c39482b96111..fac19cbc51d1 100644

--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c

@@ -2209,10 +2209,11 @@ int serial8250_do_startup(struct uart_port *port)
        /*
         * Clear the FIFO buffers and disable them.
         * (they will be reenabled in set_termios())
         */
        serial8250_clear_fifos(up);
+       serial_out(up, UART_FCR, 0);

        /*
         * Clear the interrupt registers.
         */
        serial_port_in(port, UART_LSR);

This helps, but it only addresses one part of one of the 4 reasons I
listed as motivation for my revert. For example serial8250_do_shutdown()
also clearly intends to disable the FIFOs.

OK. So, let's fix that :-)

By all means, it would be really nice to push forward and fix the garbage
issue on JZ4780, as well as the transmission issue on AM335x.

AM335x is a wildly popular platform, and it's not funny to break it.
So, let's please stop discussing which board we'll break and just fix both.
-- 
Ezequiel García, VanguardiaSur
www.vanguardiasur.com.ar