[PATCH v4 0/2] Allow imx6qp PU domain off in suspend

[PATCH v4 0/2] Allow imx6qp PU domain off in suspend

[Leonard Crestez]

On imx6qp power gating on the PU domain is disabled because of errata
ERR009619. However power gating during suspend/resume can still be
performed.

Implemented with a new core flag because otherwise distinguishing
between "runtime off" and "suspend off" is very complicated.

Link to v3 for previous attempt: https://lkml.org/lkml/2018/7/6/698

The imx vendor tree has been doing this for a many years but it uses
direct calls from platform suspend to GPC driver.

Link to v1 for similar attempt: https://lkml.org/lkml/2018/7/2/357

Leonard Crestez (2):
  PM / Domains: Add GENPD_FLAG_NO_RUNTIME_OFF flag
  soc: imx: gpc: Use GENPD_FLAG_NO_RUNTIME_OFF for ERR009619

 drivers/base/power/domain.c |  8 ++++++--
 drivers/soc/imx/gpc.c       | 13 +++++++++++--
 include/linux/pm_domain.h   |  4 ++++
 3 files changed, 21 insertions(+), 4 deletions(-)

-- 
2.17.1

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v4 1/2] PM / Domains: Add GENPD_FLAG_NO_RUNTIME_OFF flag

[Leonard Crestez]

This is for power domains which can only be powered off for suspend but
not as part of runtime PM.

Suggested-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
---
 drivers/base/power/domain.c | 8 ++++++--
 include/linux/pm_domain.h   | 4 ++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 189d7e14c611..f502218a0ddb 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -126,10 +126,11 @@ static const struct genpd_lock_ops genpd_spin_ops = {
 #define genpd_status_on(genpd)		(genpd->status == GPD_STATE_ACTIVE)
 #define genpd_is_irq_safe(genpd)	(genpd->flags & GENPD_FLAG_IRQ_SAFE)
 #define genpd_is_always_on(genpd)	(genpd->flags & GENPD_FLAG_ALWAYS_ON)
 #define genpd_is_active_wakeup(genpd)	(genpd->flags & GENPD_FLAG_ACTIVE_WAKEUP)
 #define genpd_is_cpu_domain(genpd)	(genpd->flags & GENPD_FLAG_CPU_DOMAIN)
+#define genpd_is_no_runtime_off(genpd)	(genpd->flags & GENPD_FLAG_NO_RUNTIME_OFF)
 
 static inline bool irq_safe_dev_in_no_sleep_domain(struct device *dev,
 		const struct generic_pm_domain *genpd)
 {
 	bool ret;
@@ -513,11 +514,13 @@ static int genpd_power_off(struct generic_pm_domain *genpd, bool one_dev_on,
 	/*
 	 * Abort power off for the PM domain in the following situations:
 	 * (1) The domain is configured as always on.
 	 * (2) When the domain has a subdomain being powered on.
 	 */
-	if (genpd_is_always_on(genpd) || atomic_read(&genpd->sd_count) > 0)
+	if (genpd_is_always_on(genpd) ||
+			genpd_is_no_runtime_off(genpd) ||
+			atomic_read(&genpd->sd_count) > 0)
 		return -EBUSY;
 
 	list_for_each_entry(pdd, &genpd->dev_list, list_node) {
 		enum pm_qos_flags_status stat;
 
@@ -1813,11 +1816,12 @@ int pm_genpd_init(struct generic_pm_domain *genpd,
 		genpd->dev_ops.stop = pm_clk_suspend;
 		genpd->dev_ops.start = pm_clk_resume;
 	}
 
 	/* Always-on domains must be powered on at initialization. */
-	if (genpd_is_always_on(genpd) && !genpd_status_on(genpd))
+	if ((genpd_is_always_on(genpd) || genpd_is_no_runtime_off(genpd)) &&
+			!genpd_status_on(genpd))
 		return -EINVAL;
 
 	if (genpd_is_cpu_domain(genpd) &&
 	    !zalloc_cpumask_var(&genpd->cpus, GFP_KERNEL))
 		return -ENOMEM;
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index bc82e74560ee..c9f3137e2c00 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -51,16 +51,20 @@
  *				deploy idle power management support for CPUs
  *				and groups of CPUs. Note that, the backend
  *				driver must then comply with the so called,
  *				last-man-standing algorithm, for the CPUs in the
  *				PM domain.
+ *
+ * GENPD_FLAG_NO_RUNTIME_OFF:	Instructs genpd to always keep the PM domain
+ *				powered on except for system suspend.
  */
 #define GENPD_FLAG_PM_CLK	 (1U << 0)
 #define GENPD_FLAG_IRQ_SAFE	 (1U << 1)
 #define GENPD_FLAG_ALWAYS_ON	 (1U << 2)
 #define GENPD_FLAG_ACTIVE_WAKEUP (1U << 3)
 #define GENPD_FLAG_CPU_DOMAIN	 (1U << 4)
+#define GENPD_FLAG_NO_RUNTIME_OFF (1U << 5) /* Never powered off by RPM */
 
 enum gpd_status {
 	GPD_STATE_ACTIVE = 0,	/* PM domain is active */
 	GPD_STATE_POWER_OFF,	/* PM domain is off */
 };
-- 
2.17.1

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v4 2/2] soc: imx: gpc: Use GENPD_FLAG_NO_RUNTIME_OFF for ERR009619

[Leonard Crestez]

This allows PU to be turned off in suspend and save power.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
---
 drivers/soc/imx/gpc.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/soc/imx/gpc.c b/drivers/soc/imx/gpc.c
index a8f1e47ce698..4dd493eccc98 100644
--- a/drivers/soc/imx/gpc.c
+++ b/drivers/soc/imx/gpc.c
@@ -427,14 +427,23 @@ static int imx_gpc_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "failed to init regmap: %d\n",
 			ret);
 		return ret;
 	}
 
-	/* Disable PU power down in normal operation if ERR009619 is present */
+	/*
+	 * Disable PU power down by runtime PM if ERR009619 is present.
+	 *
+	 * The PRE clock will be paused for several cycles when turning on the
+	 * PU domain LDO from power down state. If PRE is in use at that time,
+	 * the IPU/PRG cannot get the correct display data from the PRE.
+	 *
+	 * This is not a concern when the whole system enters suspend state, so
+	 * it's safe to power down PU in this case.
+	 */
 	if (of_id_data->err009619_present)
 		imx_gpc_domains[GPC_PGC_DOMAIN_PU].base.flags |=
-				GENPD_FLAG_ALWAYS_ON;
+				GENPD_FLAG_NO_RUNTIME_OFF;
 
 	/* Keep DISP always on if ERR006287 is present */
 	if (of_id_data->err006287_present)
 		imx_gpc_domains[GPC_PGC_DOMAIN_DISPLAY].base.flags |=
 				GENPD_FLAG_ALWAYS_ON;
-- 
2.17.1

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH v4 1/2] PM / Domains: Add GENPD_FLAG_NO_RUNTIME_OFF flag

[Ulf Hansson]

On Fri, 26 Apr 2019 at 23:38, Leonard Crestez <leonard.crestez@nxp.com> wrote:
>
> This is for power domains which can only be powered off for suspend but
> not as part of runtime PM.
>
> Suggested-by: Ulf Hansson <ulf.hansson@linaro.org>
> Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
> ---
>  drivers/base/power/domain.c | 8 ++++++--
>  include/linux/pm_domain.h   | 4 ++++
>  2 files changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> index 189d7e14c611..f502218a0ddb 100644
> --- a/drivers/base/power/domain.c
> +++ b/drivers/base/power/domain.c
> @@ -126,10 +126,11 @@ static const struct genpd_lock_ops genpd_spin_ops = {
>  #define genpd_status_on(genpd)         (genpd->status == GPD_STATE_ACTIVE)
>  #define genpd_is_irq_safe(genpd)       (genpd->flags & GENPD_FLAG_IRQ_SAFE)
>  #define genpd_is_always_on(genpd)      (genpd->flags & GENPD_FLAG_ALWAYS_ON)
>  #define genpd_is_active_wakeup(genpd)  (genpd->flags & GENPD_FLAG_ACTIVE_WAKEUP)
>  #define genpd_is_cpu_domain(genpd)     (genpd->flags & GENPD_FLAG_CPU_DOMAIN)
> +#define genpd_is_no_runtime_off(genpd) (genpd->flags & GENPD_FLAG_NO_RUNTIME_OFF)

May I suggest to switch the name to, GENPD_FLAG_RUNTIME_ON.

Other than that, this looks good to me!

Kind regards
Uffe

>
>  static inline bool irq_safe_dev_in_no_sleep_domain(struct device *dev,
>                 const struct generic_pm_domain *genpd)
>  {
>         bool ret;
> @@ -513,11 +514,13 @@ static int genpd_power_off(struct generic_pm_domain *genpd, bool one_dev_on,
>         /*
>          * Abort power off for the PM domain in the following situations:
>          * (1) The domain is configured as always on.
>          * (2) When the domain has a subdomain being powered on.
>          */
> -       if (genpd_is_always_on(genpd) || atomic_read(&genpd->sd_count) > 0)
> +       if (genpd_is_always_on(genpd) ||
> +                       genpd_is_no_runtime_off(genpd) ||
> +                       atomic_read(&genpd->sd_count) > 0)
>                 return -EBUSY;
>
>         list_for_each_entry(pdd, &genpd->dev_list, list_node) {
>                 enum pm_qos_flags_status stat;
>
> @@ -1813,11 +1816,12 @@ int pm_genpd_init(struct generic_pm_domain *genpd,
>                 genpd->dev_ops.stop = pm_clk_suspend;
>                 genpd->dev_ops.start = pm_clk_resume;
>         }
>
>         /* Always-on domains must be powered on at initialization. */
> -       if (genpd_is_always_on(genpd) && !genpd_status_on(genpd))
> +       if ((genpd_is_always_on(genpd) || genpd_is_no_runtime_off(genpd)) &&
> +                       !genpd_status_on(genpd))
>                 return -EINVAL;
>
>         if (genpd_is_cpu_domain(genpd) &&
>             !zalloc_cpumask_var(&genpd->cpus, GFP_KERNEL))
>                 return -ENOMEM;
> diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
> index bc82e74560ee..c9f3137e2c00 100644
> --- a/include/linux/pm_domain.h
> +++ b/include/linux/pm_domain.h
> @@ -51,16 +51,20 @@
>   *                             deploy idle power management support for CPUs
>   *                             and groups of CPUs. Note that, the backend
>   *                             driver must then comply with the so called,
>   *                             last-man-standing algorithm, for the CPUs in the
>   *                             PM domain.
> + *
> + * GENPD_FLAG_NO_RUNTIME_OFF:  Instructs genpd to always keep the PM domain
> + *                             powered on except for system suspend.
>   */
>  #define GENPD_FLAG_PM_CLK       (1U << 0)
>  #define GENPD_FLAG_IRQ_SAFE     (1U << 1)
>  #define GENPD_FLAG_ALWAYS_ON    (1U << 2)
>  #define GENPD_FLAG_ACTIVE_WAKEUP (1U << 3)
>  #define GENPD_FLAG_CPU_DOMAIN   (1U << 4)
> +#define GENPD_FLAG_NO_RUNTIME_OFF (1U << 5) /* Never powered off by RPM */
>
>  enum gpd_status {
>         GPD_STATE_ACTIVE = 0,   /* PM domain is active */
>         GPD_STATE_POWER_OFF,    /* PM domain is off */
>  };
> --
> 2.17.1
>

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH v4 1/2] PM / Domains: Add GENPD_FLAG_NO_RUNTIME_OFF flag

[Leonard Crestez]

On 4/29/2019 12:11 PM, Ulf Hansson wrote:
> On Fri, 26 Apr 2019 at 23:38, Leonard Crestez <leonard.crestez@nxp.com> wrote:
>>
>> This is for power domains which can only be powered off for suspend but
>> not as part of runtime PM.
>>
>> @@ -126,10 +126,11 @@ static const struct genpd_lock_ops genpd_spin_ops = {
>>   #define genpd_status_on(genpd)         (genpd->status == GPD_STATE_ACTIVE)
>>   #define genpd_is_irq_safe(genpd)       (genpd->flags & GENPD_FLAG_IRQ_SAFE)
>>   #define genpd_is_always_on(genpd)      (genpd->flags & GENPD_FLAG_ALWAYS_ON)
>>   #define genpd_is_active_wakeup(genpd)  (genpd->flags & GENPD_FLAG_ACTIVE_WAKEUP)
>>   #define genpd_is_cpu_domain(genpd)     (genpd->flags & GENPD_FLAG_CPU_DOMAIN)
>> +#define genpd_is_no_runtime_off(genpd) (genpd->flags & GENPD_FLAG_NO_RUNTIME_OFF) >
> May I suggest to switch the name to, GENPD_FLAG_RUNTIME_ON.
> 
> Other than that, this looks good to me!

Then it's easy to confuse genpd_status_on with genpd_is_runtime_on. How 
about genpd_is_rpm_always_on?

--
Regards,
Leonard

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH v4 1/2] PM / Domains: Add GENPD_FLAG_NO_RUNTIME_OFF flag

[Ulf Hansson]

On Mon, 29 Apr 2019 at 16:39, Leonard Crestez <leonard.crestez@nxp.com> wrote:
>
> On 4/29/2019 12:11 PM, Ulf Hansson wrote:
> > On Fri, 26 Apr 2019 at 23:38, Leonard Crestez <leonard.crestez@nxp.com> wrote:
> >>
> >> This is for power domains which can only be powered off for suspend but
> >> not as part of runtime PM.
> >>
> >> @@ -126,10 +126,11 @@ static const struct genpd_lock_ops genpd_spin_ops = {
> >>   #define genpd_status_on(genpd)         (genpd->status == GPD_STATE_ACTIVE)
> >>   #define genpd_is_irq_safe(genpd)       (genpd->flags & GENPD_FLAG_IRQ_SAFE)
> >>   #define genpd_is_always_on(genpd)      (genpd->flags & GENPD_FLAG_ALWAYS_ON)
> >>   #define genpd_is_active_wakeup(genpd)  (genpd->flags & GENPD_FLAG_ACTIVE_WAKEUP)
> >>   #define genpd_is_cpu_domain(genpd)     (genpd->flags & GENPD_FLAG_CPU_DOMAIN)
> >> +#define genpd_is_no_runtime_off(genpd) (genpd->flags & GENPD_FLAG_NO_RUNTIME_OFF) >
> > May I suggest to switch the name to, GENPD_FLAG_RUNTIME_ON.
> >
> > Other than that, this looks good to me!
>
> Then it's easy to confuse genpd_status_on with genpd_is_runtime_on. How
> about genpd_is_rpm_always_on?

Even better, let's take that.

Kind regards
Uffe

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel