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    SubjectRe: [RFC PATCH] always probe UART HW when options are not specified
    On 01/12/2016 10:37 AM, Mason wrote:
    > On 11/01/2016 20:06, Peter Hurley wrote:
    >
    >> I don't have enough information to suggest what you "should" use
    >> here.
    >>
    >> Is this going to be a shipping product?
    >> Is it single-core?
    >> etc.
    >>
    >> And what is your purpose for outputting early boot information
    >> before loading the serial driver which does provide console output?
    >
    > I'm not sure exactly which board Sebastian has in mind, but I've been
    > using the SERIAL_8250_RT288X driver on my Tango4 board.

    For the record, I'm using a SoC emulator, and thus do not have a
    bootloader per se and there are a bunch of other things that I cannot
    count on.
    The emulator has the UART pre-setup, so I just need Linux to take over
    without changing the parameters.
    Ideally, I would like to have the same image of Linux+DT to start in any
    instance of the emulator or real chips, regardless of the clock ratios,
    that's why I sort of need Linux to not change the UART speed, which is
    quite tricky because there are no clock generators in the emulator.

    NOTE: on my tree I'm using the patch I previously submitted here, so
    Linux is probing the UART so it works for all my cases, but I would like
    to go back to a standard tree.

    >
    > Note: calling the UART driver "Au1x00/RT288x" is a bit of a misnomer,
    > as these are names of SoCs using that distinct register layout.
    > The actual IP is probably the 16550-compatible Palmchip BK-3103.
    > https://sites.google.com/a/palmchiptech.com/palmchiptech/product-services/hardware-services/ip-cores/bk-3103
    > (Not sure that this website is legitimate, though.)
    >
    > When I need earlyprintk support, I use this patch from Mans:
    > http://thread.gmane.org/gmane.linux.kernel/2081016
    >
    > Regards.
    >

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