[PATCH 2/4] opp: Track device's resources configuration status

[Viresh Kumar]

The OPP core needs to track if the resources of devices are enabled or
configured or not, as it disables the resources when target_freq is set
to 0.

Handle that with a separate variable to make it easy to maintain.

Also note that we will unconditionally call clk_set_rate() in the case
where the resources are getting enabled again. This shouldn't have any
side effects anyway.

Signed-off-by: Viresh Kumar <viresh.ku...@linaro.org>
---
 drivers/opp/core.c | 37 ++++++++++++++++++-------------------
 drivers/opp/opp.h  |  2 ++
 2 files changed, 20 insertions(+), 19 deletions(-)

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 9668ea04cc80..e8882e7fd8a5 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -888,22 +888,18 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long 
target_freq)
        }
 
        if (unlikely(!target_freq)) {
+               ret = 0;
+
+               if (!opp_table->enabled)
+                       goto put_opp_table;
+
                /*
                 * Some drivers need to support cases where some platforms may
                 * have OPP table for the device, while others don't and
                 * opp_set_rate() just needs to behave like clk_set_rate().
                 */
-               if (!_get_opp_count(opp_table)) {
-                       ret = 0;
-                       goto put_opp_table;
-               }
-
-               if (!opp_table->required_opp_tables && !opp_table->regulators &&
-                   !opp_table->paths) {
-                       dev_err(dev, "target frequency can't be 0\n");
-                       ret = -EINVAL;
+               if (!_get_opp_count(opp_table))
                        goto put_opp_table;
-               }
 
                ret = _set_opp_bw(opp_table, NULL, dev, true);
                if (ret)
@@ -915,6 +911,9 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long 
target_freq)
                }
 
                ret = _set_required_opps(dev, opp_table, NULL);
+               if (!ret)
+                       opp_table->enabled = false;
+
                goto put_opp_table;
        }
 
@@ -933,14 +932,11 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long 
target_freq)
        old_freq = clk_get_rate(clk);
 
        /* Return early if nothing to do */
-       if (old_freq == freq) {
-               if (!opp_table->required_opp_tables && !opp_table->regulators &&
-                   !opp_table->paths) {
-                       dev_dbg(dev, "%s: old/new frequencies (%lu Hz) are 
same, nothing to do\n",
-                               __func__, freq);
-                       ret = 0;
-                       goto put_opp_table;
-               }
+       if (opp_table->enabled && old_freq == freq) {
+               dev_dbg(dev, "%s: old/new frequencies (%lu Hz) are same, 
nothing to do\n",
+                       __func__, freq);
+               ret = 0;
+               goto put_opp_table;
        }
 
        /*
@@ -1001,8 +997,11 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long 
target_freq)
                        dev_err(dev, "Failed to set required opps: %d\n", ret);
        }
 
-       if (!ret)
+       if (!ret) {
                ret = _set_opp_bw(opp_table, opp, dev, false);
+               if (!ret)
+                       opp_table->enabled = true;
+       }
 
 put_opp:
        dev_pm_opp_put(opp);
diff --git a/drivers/opp/opp.h b/drivers/opp/opp.h
index e51646ff279e..bd35802acc6e 100644
--- a/drivers/opp/opp.h
+++ b/drivers/opp/opp.h
@@ -152,6 +152,7 @@ enum opp_table_access {
  * property).
  * @paths: Interconnect path handles
  * @path_count: Number of interconnect paths
+ * @enabled: Set to true if the device's resources are enabled/configured.
  * @genpd_performance_state: Device's power domain support performance state.
  * @is_genpd: Marks if the OPP table belongs to a genpd.
  * @set_opp: Platform specific set_opp callback
@@ -198,6 +199,7 @@ struct opp_table {
        bool regulator_enabled;
        struct icc_path **paths;
        unsigned int path_count;
+       bool enabled;
        bool genpd_performance_state;
        bool is_genpd;
 
-- 
2.14.1