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    SubjectRe: [PATCH 3/3] ptp_qoriq: convert to use module parameters for initialization
    On Mon, Jul 30, 2018 at 06:01:54PM +0800, Yangbo Lu wrote:
    > The ptp_qoriq driver initialized the 1588 timer with the
    > configurations provided by the properties of device tree
    > node. For example,
    >
    > fsl,tclk-period = <5>;
    > fsl,tmr-prsc = <2>;
    > fsl,tmr-add = <0xaaaaaaab>;
    > fsl,tmr-fiper1 = <999999995>;
    > fsl,tmr-fiper2 = <99990>;
    > fsl,max-adj = <499999999>;
    >
    > These things actually were runtime configurations which
    > were not proper to be put into dts.

    That is debatable. While I agree that the dts isn't ideal for these,
    still it is the lesser of two or more evils.

    > This patch is to convert
    > to use module parameters for 1588 timer initialization, and
    > to support initial register values calculation.

    It is hard for me to understand how using module parameters improves
    the situation.

    > If the parameters are not provided, the driver will calculate
    > register values with a set of default parameters. With this
    > patch, those dts properties are no longer needed for new
    > platform to support 1588 timer, and many QorIQ DPAA platforms
    > (some P series and T series platforms of PowerPC, and some
    > LS series platforms of ARM64) could use this driver for their
    > fman ptp timer with default module parameters. However, this
    > patch didn't remove the dts method. Because there were still
    > many old platforms using the dts method. We need to clean up
    > their dts files, verify module parameters on them, and convert
    > them to the new method gradually in case of breaking any
    > function.

    In addition, like it or not, because the dts is an ABI, you must
    continue support of the dts values as a legacy option.

    Thanks,
    Richard

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