From: Michal Simek Date: Tue, 10 Apr 2018 13:32:28 +0000 (+0200) Subject: earlycon: Initialize port->uartclk based on clock-frequency property X-Git-Tag: v4.14.72~13 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=a44d267a67e974fd0370ae0e0a691f9e59100462;p=users%2Fjedix%2Flinux-maple.git earlycon: Initialize port->uartclk based on clock-frequency property commit 814453adea7d081ad8917aa0f32d6a14165a3563 upstream. 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. [-stable comment: commit 31cb9a8575ca ("earlycon: initialise baud field of earlycon device structure") has changed 8250_early.c behavior which now tries to setup UART speed. Ignoring clock-frequency results in wrong value of calculated divisor & malformed early console output.] Fixes: 31cb9a8575ca ("earlycon: initialise baud field of earlycon device structure") Signed-off-by: Michal Simek [rmilecki: add -stable comment and Fixes tag] Signed-off-by: Rafał Miłecki Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c index ac667b47f1997..05ba1875bb3e8 100644 --- a/drivers/tty/serial/earlycon.c +++ b/drivers/tty/serial/earlycon.c @@ -289,6 +289,10 @@ 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,