On Mon, Oct 10 2016 at 02:40 -0600, Ulf Hansson wrote:

On 8 October 2016 at 00:36, Lina Iyer [off-list ref] wrote:

quoted

Allow PM Domain states to be defined dynamically by the drivers. This
removes the limitation on the maximum number of states possible for a
domain.

Cc: Axel Haslam <redacted>
Suggested-by: Ulf Hansson <redacted>
Signed-off-by: Lina Iyer <redacted>
---
 arch/arm/mach-imx/gpc.c     | 17 ++++++++++-------
 drivers/base/power/domain.c | 36 ++++++++++++++++++++++++------------
 include/linux/pm_domain.h   |  5 ++---
 3 files changed, 36 insertions(+), 22 deletions(-)

diff --git a/arch/arm/mach-imx/gpc.c b/arch/arm/mach-imx/gpc.c
index 0df062d..57a410b 100644
--- a/arch/arm/mach-imx/gpc.c
+++ b/arch/arm/mach-imx/gpc.c

@@ -380,13 +380,6 @@ static struct pu_domain imx6q_pu_domain = {
                .name = "PU",
                .power_off = imx6q_pm_pu_power_off,
                .power_on = imx6q_pm_pu_power_on,
-               .states = {
-                       [0] = {
-                               .power_off_latency_ns = 25000,
-                               .power_on_latency_ns = 2000000,
-                       },
-               },
-               .state_count = 1,
        },
 };

@@ -430,6 +423,16 @@ static int imx_gpc_genpd_init(struct device *dev, struct regulator *pu_reg)
        if (!IS_ENABLED(CONFIG_PM_GENERIC_DOMAINS))
                return 0;

+       imx6q_pu_domain.base.states = devm_kzalloc(dev,
+                                       sizeof(*imx6q_pu_domain.base.states),
+                                       GFP_KERNEL);
+       if (!imx6q_pu_domain.base.states)
+               return -ENOMEM;
+
+       imx6q_pu_domain.base.states[0].power_off_latency_ns = 25000;
+       imx6q_pu_domain.base.states[0].power_on_latency_ns = 2000000;
+       imx6q_pu_domain.base.state_count = 1;
+
        pm_genpd_init(&imx6q_pu_domain.base, NULL, false);
        return of_genpd_add_provider_onecell(dev->of_node,
                                             &imx_gpc_onecell_data);

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index e023066..4e87170 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c

@@ -1282,6 +1282,21 @@ out:
 }
 EXPORT_SYMBOL_GPL(pm_genpd_remove_subdomain);

+static int genpd_set_default_power_state(struct generic_pm_domain *genpd)
+{
+       struct genpd_power_state *state;
+
+       state = kzalloc(sizeof(*state), GFP_KERNEL);
+       if (!state)
+               return -ENOMEM;
+
+       genpd->states = state;
+       genpd->state_count = 1;
+       genpd->free = state;
+
+       return 0;
+}
+
 /**
  * pm_genpd_init - Initialize a generic I/O PM domain object.
  * @genpd: PM domain object to initialize.

@@ -1293,6 +1308,8 @@ EXPORT_SYMBOL_GPL(pm_genpd_remove_subdomain);
 int pm_genpd_init(struct generic_pm_domain *genpd,
                  struct dev_power_governor *gov, bool is_off)
 {
+       int ret;
+
        if (IS_ERR_OR_NULL(genpd))
                return -EINVAL;

@@ -1325,19 +1342,12 @@ int pm_genpd_init(struct generic_pm_domain *genpd,
                genpd->dev_ops.start = pm_clk_resume;
        }

-       if (genpd->state_idx >= GENPD_MAX_NUM_STATES) {
-               pr_warn("Initial state index out of bounds.\n");
-               genpd->state_idx = GENPD_MAX_NUM_STATES - 1;
-       }
-
-       if (genpd->state_count > GENPD_MAX_NUM_STATES) {
-               pr_warn("Limiting states to  %d\n", GENPD_MAX_NUM_STATES);
-               genpd->state_count = GENPD_MAX_NUM_STATES;
-       }
-
        /* Use only one "off" state if there were no states declared */
-       if (genpd->state_count == 0)
-               genpd->state_count = 1;
+       if (genpd->state_count == 0) {
+               ret = genpd_set_default_power_state(genpd);
+               if (ret)
+                       return ret;
+       }

        mutex_lock(&gpd_list_lock);
        list_add(&genpd->gpd_list_node, &gpd_list);

@@ -1374,6 +1384,8 @@ static int genpd_remove(struct generic_pm_domain *genpd)
                kfree(link);
        }

+       kfree(genpd->free);
+

To be safe, let's move this after cancel_work_sync() - as to prevent
no accesses is made to ->states pointer after you have freed it.

OK

Thanks,
Lina

quoted

        list_del(&genpd->gpd_list_node);
        mutex_unlock(&genpd->lock);
        cancel_work_sync(&genpd->power_off_work);

diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index a09fe5c..de1d8f3 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h

@@ -19,8 +19,6 @@
 /* Defines used for the flags field in the struct generic_pm_domain */
 #define GENPD_FLAG_PM_CLK      (1U << 0) /* PM domain uses PM clk */

-#define GENPD_MAX_NUM_STATES   8 /* Number of possible low power states */
-
 enum gpd_status {
        GPD_STATE_ACTIVE = 0,   /* PM domain is active */
        GPD_STATE_POWER_OFF,    /* PM domain is off */

@@ -70,9 +68,10 @@ struct generic_pm_domain {
        void (*detach_dev)(struct generic_pm_domain *domain,
                           struct device *dev);
        unsigned int flags;             /* Bit field of configs for genpd */
-       struct genpd_power_state states[GENPD_MAX_NUM_STATES];
+       struct genpd_power_state *states;
        unsigned int state_count; /* number of states */
        unsigned int state_idx; /* state that genpd will go to when off */
+       void *free; /* Free the state that was allocated for default */

 };

--

2.7.4

After the minor change suggested above, you may add my ack.

Kind regards
Uffe