From a9236a0aa7d7f52a974cc7eaa971fae92aa477c5 Mon Sep 17 00:00:00 2001 From: Ulf Hansson Date: Mon, 2 Jan 2023 16:18:27 +0530 Subject: [PATCH 1/2] PM: domains: Allow a genpd consumer to require a synced power off Some genpd providers doesn't ensure that it has turned off at hardware. This is fine until the consumer really requires during some special scenarios that the power domain collapse at hardware before it is turned ON again. An example is the reset sequence of Adreno GPU which requires that the 'gpucc cx gdsc' power domain should move to OFF state in hardware at least once before turning in ON again to clear the internal state. Signed-off-by: Ulf Hansson Signed-off-by: Akhil P Oommen Reviewed-by: Bjorn Andersson Signed-off-by: Bjorn Andersson Link: https://lore.kernel.org/r/20230102161757.v5.1.I3e6b1f078ad0f1ca9358c573daa7b70ec132cdbe@changeid --- drivers/base/power/domain.c | 26 ++++++++++++++++++++++++++ include/linux/pm_domain.h | 5 +++++ 2 files changed, 31 insertions(+) diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 967bcf9d415e..84662d338188 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -519,6 +519,31 @@ ktime_t dev_pm_genpd_get_next_hrtimer(struct device *dev) } EXPORT_SYMBOL_GPL(dev_pm_genpd_get_next_hrtimer); +/* + * dev_pm_genpd_synced_poweroff - Next power off should be synchronous + * + * @dev: A device that is attached to the genpd. + * + * Allows a consumer of the genpd to notify the provider that the next power off + * should be synchronous. + * + * It is assumed that the users guarantee that the genpd wouldn't be detached + * while this routine is getting called. + */ +void dev_pm_genpd_synced_poweroff(struct device *dev) +{ + struct generic_pm_domain *genpd; + + genpd = dev_to_genpd_safe(dev); + if (!genpd) + return; + + genpd_lock(genpd); + genpd->synced_poweroff = true; + genpd_unlock(genpd); +} +EXPORT_SYMBOL_GPL(dev_pm_genpd_synced_poweroff); + static int _genpd_power_on(struct generic_pm_domain *genpd, bool timed) { unsigned int state_idx = genpd->state_idx; @@ -562,6 +587,7 @@ static int _genpd_power_on(struct generic_pm_domain *genpd, bool timed) out: raw_notifier_call_chain(&genpd->power_notifiers, GENPD_NOTIFY_ON, NULL); + genpd->synced_poweroff = false; return 0; err: raw_notifier_call_chain(&genpd->power_notifiers, GENPD_NOTIFY_OFF, diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index 1cd41bdf73cf..f776fb93eaa0 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -136,6 +136,7 @@ struct generic_pm_domain { unsigned int prepared_count; /* Suspend counter of prepared devices */ unsigned int performance_state; /* Aggregated max performance state */ cpumask_var_t cpus; /* A cpumask of the attached CPUs */ + bool synced_poweroff; /* A consumer needs a synced poweroff */ int (*power_off)(struct generic_pm_domain *domain); int (*power_on)(struct generic_pm_domain *domain); struct raw_notifier_head power_notifiers; /* Power on/off notifiers */ @@ -235,6 +236,7 @@ int dev_pm_genpd_add_notifier(struct device *dev, struct notifier_block *nb); int dev_pm_genpd_remove_notifier(struct device *dev); void dev_pm_genpd_set_next_wakeup(struct device *dev, ktime_t next); ktime_t dev_pm_genpd_get_next_hrtimer(struct device *dev); +void dev_pm_genpd_synced_poweroff(struct device *dev); extern struct dev_power_governor simple_qos_governor; extern struct dev_power_governor pm_domain_always_on_gov; @@ -300,6 +302,9 @@ static inline ktime_t dev_pm_genpd_get_next_hrtimer(struct device *dev) { return KTIME_MAX; } +static inline void dev_pm_genpd_synced_poweroff(struct device *dev) +{ } + #define simple_qos_governor (*(struct dev_power_governor *)(NULL)) #define pm_domain_always_on_gov (*(struct dev_power_governor *)(NULL)) #endif From 8b6af3b58cafc2cbdf6269f655b2d3731eb93c2f Mon Sep 17 00:00:00 2001 From: Akhil P Oommen Date: Mon, 2 Jan 2023 16:18:28 +0530 Subject: [PATCH 2/2] clk: qcom: gdsc: Support 'synced_poweroff' genpd flag Add support for the newly added 'synced_poweroff' genpd flag. This allows some clients (like adreno gpu driver) to request gdsc driver to ensure a votable gdsc (like gpucc cx gdsc) has collapsed at hardware. Signed-off-by: Akhil P Oommen Reviewed-by: Ulf Hansson Signed-off-by: Bjorn Andersson Link: https://lore.kernel.org/r/20230102161757.v5.2.Ic128c1df50b7fc9a6b919932a3b41a799b5ed5e8@changeid --- drivers/clk/qcom/gdsc.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c index 9e4d6ce891aa..5358e28122ab 100644 --- a/drivers/clk/qcom/gdsc.c +++ b/drivers/clk/qcom/gdsc.c @@ -136,7 +136,8 @@ static int gdsc_update_collapse_bit(struct gdsc *sc, bool val) return 0; } -static int gdsc_toggle_logic(struct gdsc *sc, enum gdsc_status status) +static int gdsc_toggle_logic(struct gdsc *sc, enum gdsc_status status, + bool wait) { int ret; @@ -149,7 +150,7 @@ static int gdsc_toggle_logic(struct gdsc *sc, enum gdsc_status status) ret = gdsc_update_collapse_bit(sc, status == GDSC_OFF); /* If disabling votable gdscs, don't poll on status */ - if ((sc->flags & VOTABLE) && status == GDSC_OFF) { + if ((sc->flags & VOTABLE) && status == GDSC_OFF && !wait) { /* * Add a short delay here to ensure that an enable * right after it was disabled does not put it in an @@ -275,7 +276,7 @@ static int gdsc_enable(struct generic_pm_domain *domain) gdsc_deassert_clamp_io(sc); } - ret = gdsc_toggle_logic(sc, GDSC_ON); + ret = gdsc_toggle_logic(sc, GDSC_ON, false); if (ret) return ret; @@ -352,7 +353,7 @@ static int gdsc_disable(struct generic_pm_domain *domain) if (sc->pwrsts == PWRSTS_RET_ON) return 0; - ret = gdsc_toggle_logic(sc, GDSC_OFF); + ret = gdsc_toggle_logic(sc, GDSC_OFF, domain->synced_poweroff); if (ret) return ret; @@ -392,7 +393,7 @@ static int gdsc_init(struct gdsc *sc) /* Force gdsc ON if only ON state is supported */ if (sc->pwrsts == PWRSTS_ON) { - ret = gdsc_toggle_logic(sc, GDSC_ON); + ret = gdsc_toggle_logic(sc, GDSC_ON, false); if (ret) return ret; }