* Janusz Krzysztofik <jmkrzyszt@xxxxxxxxx> [181123 03:18]:
> Since commit 1137ceee76ba ("ARM: OMAP1: ams-delta: Don't request unused
> GPIOs"), on-board audio has appeared muted. Believed to be unused GPIO
> pin "hookflash1", apparently set high regardless of the corresponding
> bit of "latch2" port attempted to be set low during .init_machine(),
> has been identified as the reason.
>
> According to Amstrad E3 wiki, the purpose of the pin hasn't been
> clearly identified. Original Amstrad software used to produce a high
> pulse on it when the phone was taken off hook or recall was pressed.
> With the current finding, we can assume the pin provides a kind of
> audio mute function.
>
> Proper resolution of the issue should be done in two steps:
> - resolution of an issue with the pin state not reflecting the value
> the corresponding bit of the port was attempted to be initialized
> with,
> - extension of on-board audio driver with a new control.
>
> For now, rename the pin to "audio_mute" to reflect its function and,
> as a quick fix, hogg it as output low so on-board audio can produce
> audible sound again.
>
> Fixes: 1137ceee76ba ("ARM: OMAP1: ams-delta: Don't request unused GPIOs")
> Signed-off-by: Janusz Krzysztofik <jmkrzyszt@xxxxxxxxx>
Adding into omap-for-v4.20/fixes thanks.
Tony
