[PATCH] PM / devfreq: Fix build issues with devfreq disabled

[MyungJoo Ham]

>Sender : Rob Clark <robdclark at gmail.com>
>Date : 2023-01-24 00:37 (GMT+9)
>Title : [PATCH] PM / devfreq: Fix build issues with devfreq disabled
> 
>From: Rob Clark <robdclark at chromium.org>
>
>The existing no-op shims for when PM_DEVFREQ (or an individual governor)
>only do half the job.  The governor specific config/tuning structs need
>to be available to avoid compile errors in drivers using devfreq.
>
>Fixes: 6563f60f14cb ("drm/msm/gpu: Add devfreq tuning debugfs")
>Signed-off-by: Rob Clark <robdclark at chromium.org>

Doesn't this imply that DRM_MSM should depend on PM_DEVFREQ ?

It appears that gpu/drm/msm/DRM_MSM uses PM_DEVFREQ without actually
declaring the dependency on PM_DEVFREQ.
You cannot use SIMPLE_ONDEMAND without DEVFREQ.

Cheers,
MyungJoo

>---
>Assuming this doesn't conflict with anything else landing via another
>tree, an a-b to land this via drm/msm-next would let us un-break builds.
>(And also start removing "select DEVFREQ_GOV_SIMPLE_ONDEMAND"s added in
>various places to try to work around this issue.)
>
> include/linux/devfreq.h | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
>diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
>index 4dc7cda4fd46..7fd704bb8f3d 100644
>--- a/include/linux/devfreq.h
>+++ b/include/linux/devfreq.h
>@@ -273,8 +273,8 @@ void devm_devfreq_unregister_notifier(struct device *dev,
> struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node);
> struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
>                                 const char *phandle_name, int index);
>+#endif /* CONFIG_PM_DEVFREQ */
> 
>-#if IS_ENABLED(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND)
> /**
>  * struct devfreq_simple_ondemand_data - ``void *data`` fed to struct devfreq
>  *        and devfreq_add_device
>@@ -292,9 +292,7 @@ struct devfreq_simple_ondemand_data {
>         unsigned int upthreshold;
>         unsigned int downdifferential;
> };
>-#endif
> 
>-#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
> enum devfreq_parent_dev_type {
>         DEVFREQ_PARENT_DEV,
>         CPUFREQ_PARENT_DEV,
>@@ -337,9 +335,8 @@ struct devfreq_passive_data {
>         struct notifier_block nb;
>         struct list_head cpu_data_list;
> };
>-#endif
> 
>-#else /* !CONFIG_PM_DEVFREQ */
>+#if !defined(CONFIG_PM_DEVFREQ)
> static inline struct devfreq *devfreq_add_device(struct device *dev,
>                                         struct devfreq_dev_profile *profile,
>                                         const char *governor_name,
>-- 
>2.38.1
>