On 02/11/2014 11:33 PM, Kumar Gala wrote:
On Feb 11, 2014, at 2:57 PM, Stephen N Chivers <schivers@xxxxxxxxxx> 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 <sebastian.hesselbarth@xxxxxxxxx> Date: Tue Dec 3 14:52:00 2013 +0100 OF: base: match each node compatible against all given matches first
[adding Arnd on Cc] Could be. I checked tty/serial/of_serial.c and it does not provide a compatible for "fsl,ns16550". Does reverting the patch fix the issue observed? I don't think the missing compatible is causing it, but of_serial provides a DT match for .type = "serial" just to fail later on with the error seen above. The commit in question reorders of_match_device in a way that match table order is not relevant anymore. This can cause it to match .type = "serial" first here. Rather than touching the commit, I suggest to remove the problematic .type = "serial" from the match table. It is of no use anyway. Sebastian -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
