Messages in this thread | | | Subject | Re: [RFC. PATCH] earlycon: Remove hardcoded port->uartclk initialization in of_setup_earlycon | From | Matt Redfearn <> | Date | Mon, 23 Apr 2018 14:16:50 +0100 |
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On 23/04/18 10:27, Michal Simek wrote: > There is no reason to initialize uartclk to BASE_BAUD * 16 for DT based > systems. > > Signed-off-by: Michal Simek <michal.simek@xilinx.com> > --- > > It looks like from history that portclk = BASE_BAUD * 16 was setup to > get on calculation on x86 (divisor = 1) but it shouldn't be needed on DT based > system. That's why I think that there is no DT based system which really > requires this line.
Hi Michal,
This is fine for the MIPS generic platform (tested on Boston board) which was broken by some earlycon changes a few versions ago. Also tested on a MIPS pistachio board. As long as the bootloader has configured the uart divisor, earlycon should work as long as my patch "serial: 8250_early: Only set divisor if valid clk & baud" is applied to avoid a bad divisor getting calculated.
Tested-by: Matt Redfearn <matt.redfearn@mips.com>
Thanks, Matt
> --- > drivers/tty/serial/earlycon.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c > index a24278380fec..c12b1edcdd8e 100644 > --- a/drivers/tty/serial/earlycon.c > +++ b/drivers/tty/serial/earlycon.c > @@ -244,7 +244,6 @@ int __init of_setup_earlycon(const struct earlycon_id *match, > return -ENXIO; > } > port->mapbase = addr; > - port->uartclk = BASE_BAUD * 16; > > val = of_get_flat_dt_prop(node, "reg-offset", NULL); > if (val) >
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