Re: [PATCH 06/14] ARM: kirkwood: convert uart0 to devicetree.

On Wed, Mar 07, 2012 at 09:13:04PM +0000, Arnd Bergmann wrote:

On Wednesday 07 March 2012, Jason wrote:

quoted

Grrr.  Now I'm getting frustrated.  I'm trying to boot without
earlyprintk.  Evidently, something is wrong with the above, because the
device boots all the way up (blinky lights come on), but I get no
messages after the usual "Uncompressing Linux... done, booting the
kernel."

Here's my most recent attempt:

        serial@f1012000 {
                device_type = "serial";
                compatible = "ns16550a";
                reg = <0xf1012000 0x100>; /*phys addr*/
                virt-reg = <0xfed12000>;  /*virt addr*/
                reg-shift = <2>;
                reg-io-width = <1>;
                interrupts = <33>;
                current-speed = <115200>;
                interrupt-parent = <&intc>;
                clock-frequency = <200000000>;
        };

I've looked at what is done in the powerpc dt's, but, no luck.  When
earlyprintk is enabled, I see no error messages, just:

bootconsole [earlycon0] enabled
debug: skip boot console de-registration.
...
Serial: 8250/16550 driver, 2 ports, IRQ sharing disabled

Any pointers?

My first guess was that clock-frequency is wrong, but it seems that
this one actually is correct, at least it's the same thing that
the platform code sets.

You should never need to pass the virtual address to a device,
most of all because it cannot be known to the device tree at all.
The of_serial driver (you did enable that one in Kconfig, right?)

Ugh.  Someone really needs to step up and kill the of_serial driver.  All that
stuff belongs in the core 16550 driver.

g.