Re: [PATCH 13/14] mmc: meson-gx: work around clk-stop issue

From: Kevin Hilman
Date: Mon Aug 07 2017 - 17:42:13 EST

Jerome Brunet <jbrunet@xxxxxxxxxxxx> writes:

> It seems that the signal clock is also used and required, somehow, by
> the controller it self.
> It is shown during init, when writing to CFG while the divider is set
> to 0 will crash the SoC. During voltage switch, the controller may crash
> and the card may then fail to exit busy state if the clock is stopped.
> To avoid this, it is best to keep the clock running for the controller,
> except during rate change. However, we still need to be able to gate
> the clock out of the SoC. Let's use the pinmux for this, and fallback
> to gpio mode (pulled-down) when we need to gate the clock
> Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>

Curious "feature" of the IP, but the solution looks good to me.

Reviewed-by: Kevin Hilman <khilman@xxxxxxxxxxxx>