[PATCH] clk: rockchip: add critical clock for rk3368

Am Montag, 14. September 2015, 16:19:42 schrieb Mark Rutland:

On Mon, Sep 14, 2015 at 04:06:05PM +0100, Heiko St?bner wrote:

quoted

Am Montag, 14. September 2015, 15:19:21 schrieb Mark Rutland:

quoted

On Sun, Sep 13, 2015 at 12:20:36PM +0100, Heiko St?bner wrote:

quoted

Again a result of the gpio-clock-liberation the rk3368 needs the
pclk_pd_pmu marked as critical, to boot successfully.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

FWIW: Tested-by: Mark Rutland [off-list ref]

I'm surprised that we don't describe these as critical in the DT, given
that this isn't really an internal property of the clock controller, but
rather what happens to be attached to it. That ship appears to have
sailed, however.

I wouldn't necessarily think so ... what is called critical only means
"don't turn off when walking the clock-tree upwards".

The pclk_pd_pmu for example simply supplies some more clocks we don't
handle at all currently (pclk_pmu_noc, ...). That we currently choose to
ignore those [because we don't have any code nor dt-bindings to handle
the components supplied] sounds very much like an implementation-specific
detail, not something about the hardware.

Sure, but the specific case that lead to this report was the fact that
this clock (directly?) feeds the pinctrl programming interface, and that
fact is neither described in the DT nor handled by the driver. Surely
that should be described and handled?

nope it doesn't :-) pclk_pd_pmu feeds pclk_gpio0.

Before the pinctrl patch, pclk_gpio0 was just statically on all the time, now 
it gets turned off when bank0 is not in use (between reads/writes and if no 
interrupts are enabled). This in turn makes the clock framework turn off 
pclk_pd_pmu (and thus its other unhandled child-clocks).