drm/etnaviv: make THERMAL selectable

The etnaviv driver causes a link failure if it is built-in but THERMAL
is built as a module:

  drivers/gpu/drm/etnaviv/etnaviv_gpu.o: In function `etnaviv_gpu_bind':
  etnaviv_gpu.c:(.text+0x4c4): undefined reference to `thermal_of_cooling_device_register'
  etnaviv_gpu.c:(.text+0x600): undefined reference to `thermal_cooling_device_unregister'
  drivers/gpu/drm/etnaviv/etnaviv_gpu.o: In function `etnaviv_gpu_unbind':
  etnaviv_gpu.c:(.text+0x2aac): undefined reference to `thermal_cooling_device_unregister'

Adding a Kconfig dependency on THERMAL || !THERMAL to avoid this causes
a dependency loop on x86_64:

  drivers/gpu/drm/tve200/Kconfig:1:error: recursive dependency detected!
  For a resolution refer to Documentation/kbuild/kconfig-language.txt
  subsection "Kconfig recursive dependency limitations"
  drivers/gpu/drm/tve200/Kconfig:1:       symbol DRM_TVE200 depends on CMA
  For a resolution refer to Documentation/kbuild/kconfig-language.txt
  subsection "Kconfig recursive dependency limitations"
  mm/Kconfig:489: symbol CMA is selected by DRM_ETNAVIV
  For a resolution refer to Documentation/kbuild/kconfig-language.txt
  subsection "Kconfig recursive dependency limitations"
  drivers/gpu/drm/etnaviv/Kconfig:2:      symbol DRM_ETNAVIV depends on THERMAL
  For a resolution refer to Documentation/kbuild/kconfig-language.txt
  subsection "Kconfig recursive dependency limitations"
  drivers/thermal/Kconfig:5:      symbol THERMAL is selected by ACPI_VIDEO
  For a resolution refer to Documentation/kbuild/kconfig-language.txt
  subsection "Kconfig recursive dependency limitations"
  drivers/acpi/Kconfig:189:       symbol ACPI_VIDEO is selected by BACKLIGHT_CLASS_DEVICE
  For a resolution refer to Documentation/kbuild/kconfig-language.txt
  subsection "Kconfig recursive dependency limitations"
  drivers/video/backlight/Kconfig:158:    symbol BACKLIGHT_CLASS_DEVICE is selected by DRM_PARADE_PS8622
  For a resolution refer to Documentation/kbuild/kconfig-language.txt
  subsection "Kconfig recursive dependency limitations"
  drivers/gpu/drm/bridge/Kconfig:62:      symbol DRM_PARADE_PS8622 depends on DRM_BRIDGE
  For a resolution refer to Documentation/kbuild/kconfig-language.txt
  subsection "Kconfig recursive dependency limitations"
  drivers/gpu/drm/bridge/Kconfig:1:       symbol DRM_BRIDGE is selected by DRM_TVE200

To work around this, add a new option DRM_ETNAVIV_THERMAL to optionally
enable thermal throttling support and make DRM_ETNAVIV select THERMAL
at the same time.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/gpu/drm/etnaviv/Kconfig b/drivers/gpu/drm/etnaviv/Kconfig
index a29b8f59eb15..3f58b4077767 100644
--- a/drivers/gpu/drm/etnaviv/Kconfig
+++ b/drivers/gpu/drm/etnaviv/Kconfig
@@ -6,6 +6,7 @@ config DRM_ETNAVIV
 	depends on MMU
 	select SHMEM
 	select SYNC_FILE
+	select THERMAL if DRM_ETNAVIV_THERMAL
 	select TMPFS
 	select WANT_DEV_COREDUMP
 	select CMA if HAVE_DMA_CONTIGUOUS
@@ -13,6 +14,14 @@ config DRM_ETNAVIV
 	help
 	  DRM driver for Vivante GPUs.
 
+config DRM_ETNAVIV_THERMAL
+	bool "enable ETNAVIV thermal throttling"
+	depends on DRM_ETNAVIV
+	default y
+	help
+	  Compile in support for thermal throttling.
+	  Say Y unless you want to risk burning your SoC.
+
 config DRM_ETNAVIV_REGISTER_LOGGING
 	bool "enable ETNAVIV register logging"
 	depends on DRM_ETNAVIV