Messages in this thread | | | Date | Mon, 30 Jul 2018 07:30:43 -0700 | From | Richard Cochran <> | Subject | Re: [PATCH 3/3] ptp_qoriq: convert to use module parameters for initialization |
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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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