On Friday, January 27, 2017, Chris Brandt wrote: > Due to the lack of clock status bits, we need to disable runtime pm > for all RZ/A1 peripherals. Otherwise, it is possible that a driver > will start using a peripheral before it is fully ready. > > By using pm_clk_resume immediately after we add the clock we ensure the > usage counter will never get back down to 0, and hence will always keep > the clock enabled. > > In order for dis_runtime_pm to be accessible for all relevant functions > in this file, it needed to be a global. > > Signed-off-by: Chris Brandt <[email protected]> > --- > drivers/clk/renesas/clk-mstp.c | 20 ++++++++++++++++++-- > 1 file changed, 18 insertions(+), 2 deletions(-) > > diff --git a/drivers/clk/renesas/clk-mstp.c b/drivers/clk/renesas/clk- > mstp.c > index 69cfdb9..3c91555 100644 > --- a/drivers/clk/renesas/clk-mstp.c > +++ b/drivers/clk/renesas/clk-mstp.c > @@ -59,6 +59,8 @@ struct mstp_clock { > struct mstp_clock_group *group; > }; > > +static bool dis_runtime_pm; > + > #define to_mstp_clock(_hw) container_of(_hw, struct mstp_clock, hw) > > static inline u32 cpg_mstp_read(struct mstp_clock_group *group, > @@ -216,6 +218,13 @@ static void __init cpg_mstp_clocks_init(struct > device_node *np) > if (of_device_is_compatible(np, "renesas,r7s72100-mstp-clocks")) > group->width_8bit = true; > > + /* > + * Due to the lack of clock status bits, we need to disable runtime > pm > + * for all RZ/A1 peripherals. > + */ > + if (of_device_is_compatible(np, "renesas,r7s72100-mstp-clocks")) > + dis_runtime_pm = true; > + > for (i = 0; i < MSTP_MAX_CLOCKS; ++i) > clks[i] = ERR_PTR(-ENOENT); > > @@ -314,6 +323,9 @@ int cpg_mstp_attach_dev(struct generic_pm_domain > *unused, struct device *dev) > goto fail_destroy; > } > > + if (dis_runtime_pm) > + pm_clk_resume(dev); > + > return 0; > > fail_destroy: > @@ -325,8 +337,11 @@ int cpg_mstp_attach_dev(struct generic_pm_domain > *unused, struct device *dev) > > void cpg_mstp_detach_dev(struct generic_pm_domain *unused, struct device > *dev) > { > - if (!list_empty(&dev->power.subsys_data->clock_list)) > + if (!list_empty(&dev->power.subsys_data->clock_list)) { > + if (dis_runtime_pm) > + pm_clk_suspend(dev); > pm_clk_destroy(dev); > + } > } > > void __init cpg_mstp_add_clk_domain(struct device_node *np) > @@ -344,7 +359,8 @@ void __init cpg_mstp_add_clk_domain(struct device_node > *np) > return; > > pd->name = np->name; > - pd->flags = GENPD_FLAG_PM_CLK; > + if (!dis_runtime_pm) > + pd->flags = GENPD_FLAG_PM_CLK; > pd->attach_dev = cpg_mstp_attach_dev; > pd->detach_dev = cpg_mstp_detach_dev; > pm_genpd_init(pd, &pm_domain_always_on_gov, false); > -- > 2.10.1 >
Hmm, I might actually want to hold off on this one because I'm investigating the individual drivers at the moment for flaws (I2C in particular) -Chris
