Hi Stephen, Stephen Boyd <sb...@kernel.org> wrote on Thu, 20 Dec 2018 13:09:19 -0800:
> Quoting Miquel Raynal (2018-12-19 00:03:31) > > Hi Stephen, > > > > Stephen Boyd <sb...@kernel.org> wrote on Tue, 18 Dec 2018 16:03:29 > > -0800: > > > > > Quoting Miquel Raynal (2018-12-04 11:24:37) > > > > Currently, the core->dev entry is populated only if runtime PM is > > > > enabled. Doing so prevents accessing the device structure in any > > > > case. > > > > > > > > Keep the same logic but instead of using the presence of core->dev as > > > > the only condition, also check the status of > > > > pm_runtime_enabled(). Then, we can set the core->dev pointer at any > > > > time as long as a device structure is available. > > > > > > > > This change will help supporting device links in the clock subsystem. > > > > > > > > Signed-off-by: Miquel Raynal <miquel.ray...@bootlin.com> > > > > --- > > > > drivers/clk/clk.c | 11 +++++------ > > > > 1 file changed, 5 insertions(+), 6 deletions(-) > > > > > > > > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c > > > > index af011974d4ec..b799347c5fd6 100644 > > > > --- a/drivers/clk/clk.c > > > > +++ b/drivers/clk/clk.c > > > > @@ -97,7 +97,7 @@ static int clk_pm_runtime_get(struct clk_core *core) > > > > { > > > > int ret = 0; > > > > > > > > - if (!core->dev) > > > > + if (!core->dev || !pm_runtime_enabled(core->dev)) > > > > > > This looks potentially dangerous. What if runtime PM is disabled for the > > > clk when this function is called? Shouldn't we just stash a bool away in > > > the clk_core structure when it's registered? And then we can replace the > > > check for !core->dev with a check for 'core->rpm_enabled' instead. That > > > would be a more exact transformation. > > > > Sure, I'll do that if you think there is a danger. > > I've made the change and pushed it out to the clk tree. I'm working on > some patches to change how we do parent lookups and reworking clk_get() > in the process. Take a look so we don't duplicate efforts. The code > isn't complete, but I hope to finish soon. Your device links patches can > build upon this. > > git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git > clk-parent-rewrite > Sorry for the delay and thanks for the update. I have been preempted by another issue, I will switch to clocks and propose something ASAP. Thanks, Miquèl