Re: [PATCH] net: mdio: mdio-bcm-unimac: Delay before first poll

From: Andrew Lunn
Date: Wed Dec 13 2023 - 05:58:10 EST


On Tue, Dec 12, 2023 at 04:02:49PM -0800, Justin Chen wrote:
> With a clock interval of 400 nsec and a 64 bit transactions (32 bit
> preamble & 16 bit control & 16 bit data), it is reasonable to assume
> the mdio transaction will take 25.6 usec. Add a 30 usec delay before
> the first poll to reduce the chance of a 1000-2000 usec sleep.

#define MDIO_C45 0

suggests the hardware can do C45? The timing works out different then.
Maybe add a comment by the udelay() that is assumes C22, to give a
clue to somebody who is adding C45 support the delay needs to be
re-evaluated.

Andrew