devfreq: remove FREQ_DONTSCALE return if same freq

In nvhost_pod_estimate_freq(), we return
GET_TARGET_FREQ_DONTSCALE if new frequency is same
as current frequency

And based on this return value, update_devfreq()
will just return without actually calling target()
function

But it is possible that target() function has freq
clipping of its own, and skipping target() itself
will break this

Hence in case we find new frequency same as current
frequency, do not return GET_TARGET_FREQ_DONTSCALE
Instead just return 0

Note that we still return GET_TARGET_FREQ_DONTSCALE
if governor itself is disabled, and this is
required in perf measurement cases

Bug 200245796

Change-Id: I55a3a344982c5b5441ba011cd0dd254947e89e5c
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/1251841
(cherry picked from linux-4.9 commit c6417ac88eb43501b8bf6d5351059ac2dadaf2c0)
Reviewed-on: https://git-master.nvidia.com/r/1770145
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Timo Alho <talho@nvidia.com>
Tested-by: Timo Alho <talho@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 1 insertions, 6 deletions

diff --git a/drivers/devfreq/governor_pod_scaling.c b/drivers/devfreq/governor_pod_scaling.c
index 5f84ef3ec..3ffaeb78d 100644
--- a/drivers/devfreq/governor_pod_scaling.c
+++ b/drivers/devfreq/governor_pod_scaling.c
@@ -766,11 +766,6 @@ static int nvhost_pod_estimate_freq(struct devfreq *df,
                 /* Do not do unnecessary scaling */
                 scaling_limit(df, &podgov->adjustment_frequency);
 
-                /* Round the frequency and check if we're already there */
-                if (freqlist_up(podgov, podgov->adjustment_frequency, 0) ==
-                    dev_stat.current_frequency)
-                        return GET_TARGET_FREQ_DONTSCALE;
-
                 trace_podgov_estimate_freq(df->dev.parent,
                                            df->previous_freq,
                                            podgov->adjustment_frequency);
@@ -806,7 +801,7 @@ static int nvhost_pod_estimate_freq(struct devfreq *df,
 
         if (!(*freq) ||
             (freqlist_up(podgov, *freq, 0) == dev_stat.current_frequency))
-                return GET_TARGET_FREQ_DONTSCALE;
+                return 0;
 
         podgov->last_scale = now;