Hi Mike, On Sat, Sep 27, 2014 at 05:17:32PM -0700, Mike Turquette wrote: > Quoting Maxime Ripard (2014-09-11 13:18:17) > > The current phase API doesn't look into the actual hardware to get the phase > > value, but will rather get it from a variable only set by the set_phase > > function. > > > > This will cause issue when the client driver will never call the set_phase > > function, where we can end up having a reported phase that will not match what > > the hardware has been programmed to by the bootloader or what phase is > > programmed out of reset. > > > > Add a new get_phase function for the drivers to implement so that we can get > > this value. > > > > Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> > > --- > > drivers/clk/clk.c | 10 ++++++++++ > > include/linux/clk-provider.h | 5 +++++ > > 2 files changed, 15 insertions(+) > > > > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c > > index d87661af0c72..113d75db371d 100644 > > --- a/drivers/clk/clk.c > > +++ b/drivers/clk/clk.c > > @@ -1934,6 +1934,16 @@ int __clk_init(struct device *dev, struct clk *clk) > > clk->accuracy = 0; > > > > /* > > + * Set clk's phase. > > + * Since a phase is by definition relative to its parent, just > > + * query the current clock phase, or just assume it's in phase. > > + */ > > + if (clk->ops->get_phase) > > + clk->phase = clk->ops->get_phase(clk->hw); > > + else > > + clk->phase = 0; > > I probably wasn't paying enough attention to this. Based on the > coverletter I thought that v3 would introduce something like > CLK_GET_PHASE_NOCACHE and stuff that logic into a __clk_get_phase > function? Looks like this version of the series doesn't handle phases > that can be changed by hardware (e.g. coming out of idle). > > Correct me if I am wrong, but it looks like we retrieve the phase only > once at init and then never again? The rest of the time we rely on > clk->phase to always be accurate... Yeah, I didn't have any use for it at the moment, and thought that if someone ever needed it, it would be trivial to add, so I left it out. If you want me to still do it, I can send an additional patch. Thanks! Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com
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