Re: Linux-3.14-rc2: Order of serial node compatibles in DTS files.

On Feb 11, 2014, at 2:57 PM, Stephen N Chivers [off-list ref] wrote:

I have been trial booting a 3.14-rc2 kernel for a 85xx platform 
(dtbImage).

After mounting the root filesystem there are no messages from the init 
scripts
and the serial console is not available for login.

In the kernel log messages there is:

of_serial f1004500.serial: Unknown serial port found, ignored.

The serial nodes in boards dts file are specified as:

       serial0: serial@4500 {
                       cell-index = <0>;
                       device_type = "serial";
                       compatible = "fsl,ns16550", "ns16550";
                       reg = <0x4500 0x100>;
                       clock-frequency = <0>;
                       interrupts = <0x2a 0x2>;
                       interrupt-parent = <&mpic>;
               };

Reversing the order of the compatible:

       compatible = "ns16550", "fsl,ns16550";

restores the serial console.

Linux-3.13 does not have this behaviour.

There are 49 dts files in Linux-3.14-rc2 that have the fsl,ns16550 
compatible first.

Hmm,

Wondering if this caused the issue:

commit 105353145eafb3ea919f5cdeb652a9d8f270228e
Author: Sebastian Hesselbarth [off-list ref]
Date:   Tue Dec 3 14:52:00 2013 +0100

    OF: base: match each node compatible against all given matches first


- k