Subject: Re: [PATCH 6/6] ptp_ocelot: support 4 programmable pins

From: Richard Cochran <[email-masked]>
Date: Wed, 25 Mar 2020 06:41:47 -0700

On Wed, Mar 25, 2020 at 03:08:46AM +0000, Y.b. Lu wrote:

> The calling should be like this,
> ptp_set_pinfunc (hold pincfg_mux)
> ---> ptp_disable_pinfunc
>    ---> .enable
>       ---> ptp_find_pin (hold pincfg_mux)

I see.  The call

    ptp_disable_pinfunc() --> .enable()

is really

    ptp_disable_pinfunc() --> .enable(on=0)

or disable.

All of the other drivers (except mv88e6xxx which has a bug) avoid the
deadlock by only calling ptp_find_pin() when invoked by .enable(on=1);

Of course, that is horrible, and I am going to find a way to fix it.

For now, maybe you can drop the "programmable pins" feature for your
driver?  After all, the pins are not programmable.

Thanks,
Richard