hi, On Fri, Dec 27, 2013 at 10:11:28AM +0800, Peter Chen wrote: > > > > > Add clock enable/disable at .set_suspend if the PHY has > > > > > suspend requirement, it can be benefit of power saving for > > > > > phy and the whole system (parent clock may also be disabled). > > > > > > > > > > Signed-off-by: Peter Chen <peter.chen@xxxxxxxxxxxxx> > > > > > --- > > > > > drivers/usb/phy/phy-generic.c | 10 ++++++++++ > > > > > 1 files changed, 10 insertions(+), 0 deletions(-) > > > > > > > > > > diff --git a/drivers/usb/phy/phy-generic.c b/drivers/usb/phy/phy-generic.c > > > > > index aa6d37b..4b20a97 100644 > > > > > --- a/drivers/usb/phy/phy-generic.c > > > > > +++ b/drivers/usb/phy/phy-generic.c > > > > > @@ -65,6 +65,16 @@ EXPORT_SYMBOL(usb_nop_xceiv_unregister); > > > > > > > > > > static int nop_set_suspend(struct usb_phy *x, int suspend) > > > > > { > > > > > + struct usb_phy_gen_xceiv *nop = dev_get_drvdata(x->dev); > > > > > + > > > > > + if (IS_ERR(nop->clk)) > > > > > + return 0; > > > > > + > > > > > + if (suspend) > > > > > + clk_disable_unprepare(nop->clk); > > > > > + else > > > > > + clk_prepare_enable(nop->clk); > > > > > > > > heh, this is why I don't like clk_enable_prepare(). > > > > usb_phy_set_suspend() can be called from atomic context. > > > > > > > > > > Oh, then, how can we disable/enable phy's clock at runtime/system-side > > > pm? Create another APIs like usb_phy_set_clk()? > > > > clk_prepare() on probe, clk_unprepare() on remove, > > clk_enable()/disable() on set_suspend() > > > > It will keep phy's clock prepare_count is always 1, assume one > use case, the pll clk is the parent of phy clk, it will > cause the pll clk can't be unprepared during the runtime, it > may cause the pll can't be powered off during the runtime. if you power off PHY's PLL, how will you ever notice a remote wakeup event ? How will you ever wakeup at all ? -- balbi
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