Messages in this thread | | | Date | Thu, 28 Jan 2021 02:56:25 +0100 | From | Andrew Lunn <> | Subject | Re: [PATCH] net: mdiobus: Prevent spike on MDIO bus reset signal |
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On Tue, Jan 26, 2021 at 08:33:37AM +0100, Mike Looijmans wrote: > The mdio_bus reset code first de-asserted the reset by allocating with > GPIOD_OUT_LOW, then asserted and de-asserted again. In other words, if > the reset signal defaulted to asserted, there'd be a short "spike" > before the reset. > > Instead, directly assert the reset signal using GPIOD_OUT_HIGH, this > removes the spike and also removes a line of code since the signal > is already high.
Hi Mike
Did you look at the per PHY reset? mdiobus_register_gpiod() gets the GPIO with GPIOD_OUT_LOW. mdiobus_register_device() then immediately sets it high.
So it looks like it suffers from the same problem.
Andrew
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