Thread (1 message) 1 message, 1 author, 2025-07-09

Re: Re: [PATCH] net: stmmac: Support gpio high-level reset for devices requiring it

From: Andrew Lunn <andrew@lunn.ch>
Date: 2025-07-09 12:54:45
Also in: linux-arm-kernel, lkml

On Wed, Jul 09, 2025 at 09:57:50AM +0800, lizhe wrote:
Hi, Andrew

Thx,


i conducted an experiment, and no matter whether i configured it as 

GPIO_ACTIVE_LOW or GPIO_ACTIVE_HIGH in the dts, the resulting

GPIO pin state was 0, indicating a low level.
You need to keep digging and understand why.

Scatter some printk() in the gpio core code. Does it recognise the
option in DT? Is GPIO_ACTIVE_LOW, FLAG_ACTIVE_LOW being set?

Put some prints into the actual GPIO driver, what is passed to it.

There is something interesting in gpio.txt:

Most controllers are specifying a generic flag bitfield in the last cell, so
for these, use the macros defined in
include/dt-bindings/gpio/gpio.h whenever possible:

It says 'Most'. Is the GPIO controller you are using not actually
doing this?

	Andrew
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