Hello Heiko and Doug, On Wed, Feb 15, 2017 at 2:01 PM, Heiko St?bner <heiko at sntech.de> wrote: > Am Mittwoch, 15. Februar 2017, 12:27:59 CET schrieb Javier Martinez Canillas: >> Hello Doug, >> >> On Tue, Feb 14, 2017 at 6:01 PM, Douglas Anderson <dianders at chromium.org> > wrote: >> > The PMU Cortex M0 on rk3399 is intended to be used for things like >> > DDRFreq transitions, suspend/resume, and other things that are the >> > purview of ARM Trusted Firmware and not the kernel. As such, the >> > kernel shouldn't be messing with the clocks. Add CLK_IGNORE_UNUSED to >> > these clocks. >> >> Isn't CLK_IS_CRITICAL a more suitable flag for this case? > > From the patch description it looks like the clock is expected to be > controlled from firmware in most cases as I guess the Cortex M0 will be used > for that all the time now. And the clock is not expected to run all the time. > > So I'd think clk_ignore_unused is the correct one. The whole clock-subtree for > these clocks also does not get affected by other clocks, as it is > independendly coming from PLLs. > > I see. Thanks a lot for your explanations. I just asked because CLK_IGNORE_UNUSED only prevents the clock to be disabled by clk_disable_unused() but still can be disabled if a driver explicitly looks it up and calls clk_disable() or if the clock is affected by other clocks. But I understand now that both scenarios are not possible. So yes, CLK_IGNORE_UNUSED is more suitable in this case. > Heiko Best regards, Javier
