Paul Walmsley <paul@xxxxxxxxx> writes:
> When the clockdomain layer initializes, place all clockdomains into
> software-supervised mode, and clear all wakeup and sleep dependencies
> immediately, rather than waiting for the PM code to do this later.
> This fixes a major bug where critical sleep dependencies added by the
> hwmod code are cleared during late PM init.
>
> As a side benefit, the _init_{wk,sleep}dep_usecount() functions are no
> longer needed, so remove them.
>
> Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx> did all the really hard work on
> this, identifying the problem and finding the bug.
>
> Signed-off-by: Paul Walmsley <paul@xxxxxxxxx>
> Cc: Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx>
Thanks Paul.
I'll queue this in pm-next for 2.6.37 along with the other changes that
depend on it.
Kevin
> ---
> arch/arm/mach-omap2/clockdomain.c | 110 +++++--------------------------------
> arch/arm/mach-omap2/pm34xx.c | 3 -
> 2 files changed, 15 insertions(+), 98 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/clockdomain.c b/arch/arm/mach-omap2/clockdomain.c
> index 5d80cb8..6fb61b1 100644
> --- a/arch/arm/mach-omap2/clockdomain.c
> +++ b/arch/arm/mach-omap2/clockdomain.c
> @@ -258,97 +258,6 @@ static void _omap2_clkdm_set_hwsup(struct clockdomain *clkdm, int enable)
>
> }
>
> -/**
> - * _init_wkdep_usecount - initialize wkdep usecounts to match hardware
> - * @clkdm: clockdomain to initialize wkdep usecounts
> - *
> - * Initialize the wakeup dependency usecount variables for clockdomain @clkdm.
> - * If a wakeup dependency is present in the hardware, the usecount will be
> - * set to 1; otherwise, it will be set to 0. Software should clear all
> - * software wakeup dependencies prior to calling this function if it wishes
> - * to ensure that all usecounts start at 0. No return value.
> - */
> -static void _init_wkdep_usecount(struct clockdomain *clkdm)
> -{
> - u32 v;
> - struct clkdm_dep *cd;
> -
> - if (!clkdm->wkdep_srcs)
> - return;
> -
> - for (cd = clkdm->wkdep_srcs; cd->clkdm_name; cd++) {
> - if (!omap_chip_is(cd->omap_chip))
> - continue;
> -
> - if (!cd->clkdm && cd->clkdm_name)
> - cd->clkdm = _clkdm_lookup(cd->clkdm_name);
> -
> - if (!cd->clkdm) {
> - WARN(!cd->clkdm, "clockdomain: %s: wkdep clkdm %s not "
> - "found\n", clkdm->name, cd->clkdm_name);
> - continue;
> - }
> -
> - v = prm_read_mod_bits_shift(clkdm->pwrdm.ptr->prcm_offs,
> - PM_WKDEP,
> - (1 << cd->clkdm->dep_bit));
> -
> - if (v)
> - pr_debug("clockdomain: %s: wakeup dependency already "
> - "set to wake up when %s wakes\n",
> - clkdm->name, cd->clkdm->name);
> -
> - atomic_set(&cd->wkdep_usecount, (v) ? 1 : 0);
> - }
> -}
> -
> -/**
> - * _init_sleepdep_usecount - initialize sleepdep usecounts to match hardware
> - * @clkdm: clockdomain to initialize sleepdep usecounts
> - *
> - * Initialize the sleep dependency usecount variables for clockdomain @clkdm.
> - * If a sleep dependency is present in the hardware, the usecount will be
> - * set to 1; otherwise, it will be set to 0. Software should clear all
> - * software sleep dependencies prior to calling this function if it wishes
> - * to ensure that all usecounts start at 0. No return value.
> - */
> -static void _init_sleepdep_usecount(struct clockdomain *clkdm)
> -{
> - u32 v;
> - struct clkdm_dep *cd;
> -
> - if (!cpu_is_omap34xx())
> - return;
> -
> - if (!clkdm->sleepdep_srcs)
> - return;
> -
> - for (cd = clkdm->sleepdep_srcs; cd->clkdm_name; cd++) {
> - if (!omap_chip_is(cd->omap_chip))
> - continue;
> -
> - if (!cd->clkdm && cd->clkdm_name)
> - cd->clkdm = _clkdm_lookup(cd->clkdm_name);
> -
> - if (!cd->clkdm) {
> - WARN(!cd->clkdm, "clockdomain: %s: sleepdep clkdm %s "
> - "not found\n", clkdm->name, cd->clkdm_name);
> - continue;
> - }
> -
> - v = prm_read_mod_bits_shift(clkdm->pwrdm.ptr->prcm_offs,
> - OMAP3430_CM_SLEEPDEP,
> - (1 << cd->clkdm->dep_bit));
> -
> - if (v)
> - pr_debug("clockdomain: %s: sleep dependency already "
> - "set to prevent from idling until %s "
> - "idles\n", clkdm->name, cd->clkdm->name);
> -
> - atomic_set(&cd->sleepdep_usecount, (v) ? 1 : 0);
> - }
> -};
> -
> /* Public functions */
>
> /**
> @@ -379,12 +288,17 @@ void clkdm_init(struct clockdomain **clkdms,
> _autodep_lookup(autodep);
>
> /*
> - * Ensure that the *dep_usecount registers reflect the current
> - * state of the PRCM.
> + * Put all clockdomains into software-supervised mode; PM code
> + * should later enable hardware-supervised mode as appropriate
> */
> list_for_each_entry(clkdm, &clkdm_list, node) {
> - _init_wkdep_usecount(clkdm);
> - _init_sleepdep_usecount(clkdm);
> + if (clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)
> + omap2_clkdm_wakeup(clkdm);
> + else if (clkdm->flags & CLKDM_CAN_DISABLE_AUTO)
> + omap2_clkdm_deny_idle(clkdm);
> +
> + clkdm_clear_all_wkdeps(clkdm);
> + clkdm_clear_all_sleepdeps(clkdm);
> }
> }
>
> @@ -592,6 +506,9 @@ int clkdm_clear_all_wkdeps(struct clockdomain *clkdm)
> if (!omap_chip_is(cd->omap_chip))
> continue;
>
> + if (!cd->clkdm && cd->clkdm_name)
> + cd->clkdm = _clkdm_lookup(cd->clkdm_name);
> +
> /* PRM accesses are slow, so minimize them */
> mask |= 1 << cd->clkdm->dep_bit;
> atomic_set(&cd->wkdep_usecount, 0);
> @@ -752,6 +669,9 @@ int clkdm_clear_all_sleepdeps(struct clockdomain *clkdm)
> if (!omap_chip_is(cd->omap_chip))
> continue;
>
> + if (!cd->clkdm && cd->clkdm_name)
> + cd->clkdm = _clkdm_lookup(cd->clkdm_name);
> +
> /* PRM accesses are slow, so minimize them */
> mask |= 1 << cd->clkdm->dep_bit;
> atomic_set(&cd->sleepdep_usecount, 0);
> diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
> index 429268e..772e985 100644
> --- a/arch/arm/mach-omap2/pm34xx.c
> +++ b/arch/arm/mach-omap2/pm34xx.c
> @@ -1024,9 +1024,6 @@ static int __init pwrdms_setup(struct powerdomain *pwrdm, void *unused)
> */
> static int __init clkdms_setup(struct clockdomain *clkdm, void *unused)
> {
> - clkdm_clear_all_wkdeps(clkdm);
> - clkdm_clear_all_sleepdeps(clkdm);
> -
> if (clkdm->flags & CLKDM_CAN_ENABLE_AUTO)
> omap2_clkdm_allow_idle(clkdm);
> else if (clkdm->flags & CLKDM_CAN_FORCE_SLEEP &&
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