On DT based platforms when current-speed property is present baudrate is setup. Also port->uartclk is initialized to bogus BASE_BAUD * 16 value. Drivers like uartps/ns16550 contain logic when baudrate and uartclk is used for baudrate calculation.
The patch is reading optional clock-frequency property to replace bogus BASE_BAUD * 16 calculation to have proper baudrate calculation. Signed-off-by: Michal Simek <michal.si...@xilinx.com> --- We should add documentation for current-speed, reg-offset, reg-shift, big-endian, native-endian, reg-io-width and clock-frequency to any generic location because they are all optional properties for all DT earlycon drivers through of_setup_earlycon. --- drivers/tty/serial/earlycon.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c index a24278380fec..eb1f84258c44 100644 --- a/drivers/tty/serial/earlycon.c +++ b/drivers/tty/serial/earlycon.c @@ -279,6 +279,10 @@ int __init of_setup_earlycon(const struct earlycon_id *match, if (val) early_console_dev.baud = be32_to_cpu(*val); + val = of_get_flat_dt_prop(node, "clock-frequency", NULL); + if (val) + port->uartclk = be32_to_cpu(*val); + if (options) { early_console_dev.baud = simple_strtoul(options, NULL, 0); strlcpy(early_console_dev.options, options, -- 1.9.1