On 12/16/2018 10:52 PM, Ezequiel Garcia wrote: > On Sun, 16 Dec 2018 at 18:45, Marek Vasut <marex@xxxxxxx> wrote: > [skips discussion] >> >>> Ultimately it's Greg's decision but it sounds like you're asking me to >>> say it's OK to break the JZ4780 in a stable kernel with a patch that I >>> think would be risky anyway, and I won't do that. >> >> I am saying this revert breaks AM335x, so this is a stalemate. I had a >> discussion with Ezequiel (on CC) and he seems to have a different >> smaller patch coming for this problem. >> > > Can you guys test this? Note that serial8250_do_startup has a comment > stating clearly that it has the intention of disabling the FIFOs, > so it seems this is the right thing to do. > > Paul, this removes the garbage on my CI20 (rev.1) > > 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); > > On AM335x pocketbeagle Tested-by: Marek Vasut <marex@xxxxxxx> -- Best regards, Marek Vasut
