From 41d3f09913a930369a26616eedc02339d0455498 Mon Sep 17 00:00:00 2001 From: Aaron Sierra Date: Mon, 3 Mar 2014 19:54:36 -0600 Subject: [PATCH] serial: 8250_pci: change BayTrail default uartclk The Intel BayTrail HSUART power-on default reference clock is 44.2368 MHz, but 73.728 MHz provides 0% error for additional "conventional" baud rates above 460800 (e.g. 576000, 921600, and 1152000). Signed-off-by: Aaron Sierra Reviewed-by: Heikki Krogerus Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_pci.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c index a3dbc4d97fa2..b14bcba96c25 100644 --- a/drivers/tty/serial/8250/8250_pci.c +++ b/drivers/tty/serial/8250/8250_pci.c @@ -1401,9 +1401,9 @@ byt_set_termios(struct uart_port *p, struct ktermios *termios, p->uartclk = 40000000; break; default: - m = 6912; - n = 15625; - p->uartclk = 44236800; + m = 2304; + n = 3125; + p->uartclk = 73728000; } /* Reset the clock */ @@ -3470,6 +3470,10 @@ static struct pciserial_board pci_boards[] = { .base_baud = 921600, .reg_shift = 2, }, + /* + * Intel BayTrail HSUART reference clock is 44.2368 MHz at power-on, + * but is overridden by byt_set_termios. + */ [pbn_byt] = { .flags = FL_BASE0, .num_ports = 1, -- 2.34.1