On 24/09/2019 13:20:15-0700, Stephen Boyd wrote: > Quoting Uwe (2019-09-24 05:21:47) > > On Fri, Sep 20, 2019 at 05:39:06PM +0200, Alexandre Belloni wrote: > > > Note that this was already discussed a while ago and Arnd said this > > > approach was > > > reasonable: > > > https://lore.kernel.org/lkml/6120818.MyeJZ74hYa@wuerfel/ > > > > > > drivers/clk/at91/clk-main.c | 5 ++++- > > > drivers/clk/at91/sckc.c | 20 ++++++++++++++++---- > > > 2 files changed, 20 insertions(+), 5 deletions(-) > > > > > > diff --git a/drivers/clk/at91/clk-main.c b/drivers/clk/at91/clk-main.c > > > index f607ee702c83..ccd48e7a3d74 100644 > > > --- a/drivers/clk/at91/clk-main.c > > > +++ b/drivers/clk/at91/clk-main.c > > > @@ -293,7 +293,10 @@ static int clk_main_probe_frequency(struct regmap > > > *regmap) > > > regmap_read(regmap, AT91_CKGR_MCFR, &mcfr); > > > if (mcfr & AT91_PMC_MAINRDY) > > > return 0; > > > - usleep_range(MAINF_LOOP_MIN_WAIT, MAINF_LOOP_MAX_WAIT); > > > + if (system_state < SYSTEM_RUNNING) > > > + udelay(MAINF_LOOP_MIN_WAIT); > > > + else > > > + usleep_range(MAINF_LOOP_MIN_WAIT, > > > MAINF_LOOP_MAX_WAIT); > > > > Given that this construct is introduced several times, I wonder if we > > want something like: > > > > static inline void early_usleep_range(unsigned long min, unsigned > > long max) > > { > > if (system_state < SYSTEM_RUNNING) > > udelay(min); > > else > > usleep_range(min, max); > > } > > > > Maybe, but I think the intent is to not encourage this behavior? So > providing a wrapper will make it "easy" and then we'll have to tell > users to stop calling it. Another idea would be to make usleep_range() > "do the right thing" and call udelay if the system isn't running. And > another idea from tlgx[1] is to pull the delay logic into another clk op > that we can call to see when the enable or prepare is done. That may be > possible by introducing another clk_ops callback that when present > indicates we should sleep or delay for so much time while waiting for > the prepare or enable to complete. > > [1] https://lkml.kernel.org/r/alpine.DEB.2.11.1606061448010.28031@nanos >
Do you want me to implement that now or are you planning to apply the patch in the meantime ? -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
