Re: [PATCH 7/7] net: dsa: b53: Expose PTP timestamping ioctls to userspace

From: Vladimir Oltean
Date: Fri Nov 05 2021 - 20:36:23 EST

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In reply to: Richard Cochran: "Re: [PATCH 7/7] net: dsa: b53: Expose PTP timestamping ioctls to userspace"
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On Fri, Nov 05, 2021 at 05:18:04PM -0700, Richard Cochran wrote:
> On Fri, Nov 05, 2021 at 04:28:33PM +0200, Vladimir Oltean wrote:
> > What is the expected convention exactly? There are other drivers that
> > downgrade the user application's request to what they support, and at
> > least ptp4l does not error out, it just prints a warning.
>
> Drivers may upgrade, but they may not downgrade.
>
> Which drivers downgrade? We need to fix those buggy drivers.
>
> Thanks,
> Richard

Just a quick example
https://elixir.bootlin.com/linux/v5.15/source/drivers/net/ethernet/mscc/ocelot.c#L1178
I haven't studied the whole tree, but I'm sure there are many more.