[PATCH v2 1/3] fbdev: Fix recursive dependencies wrt BACKLIGHT_CLASS_DEVICE

Thu Dec 12 21:04:43 AEDT 2024

Do not select BACKLIGHT_CLASS_DEVICE from FB_BACKLIGHT. The latter
only controls backlight support within fbdev core code and data
structures.

Make fbdev drivers depend on BACKLIGHT_CLASS_DEVICE and let users
select it explicitly. Fixes warnings about recursive dependencies,
such as

error: recursive dependency detected!
	symbol BACKLIGHT_CLASS_DEVICE is selected by FB_BACKLIGHT
	symbol FB_BACKLIGHT is selected by FB_SH_MOBILE_LCDC
	symbol FB_SH_MOBILE_LCDC depends on FB_DEVICE
	symbol FB_DEVICE depends on FB_CORE
	symbol FB_CORE is selected by DRM_GEM_DMA_HELPER
	symbol DRM_GEM_DMA_HELPER is selected by DRM_PANEL_ILITEK_ILI9341
	symbol DRM_PANEL_ILITEK_ILI9341 depends on BACKLIGHT_CLASS_DEVICE

BACKLIGHT_CLASS_DEVICE is user-selectable, so making drivers adapt to
it is the correct approach in any case. For most drivers, backlight
support is also configurable separately.

v2:
- s/BACKLIGHT_DEVICE_CLASS/BACKLIGHT_CLASS_DEVICE (Helge)
- Fix fbdev driver-dependency corner case (Arnd)

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
---
 drivers/auxdisplay/Kconfig       |  2 +-
 drivers/macintosh/Kconfig        |  1 +
 drivers/staging/fbtft/Kconfig    |  1 +
 drivers/video/fbdev/Kconfig      | 18 +++++++++++++-----
 drivers/video/fbdev/core/Kconfig |  3 +--
 5 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/drivers/auxdisplay/Kconfig b/drivers/auxdisplay/Kconfig
index 21545ffba065..8934e6ad5772 100644
--- a/drivers/auxdisplay/Kconfig
+++ b/drivers/auxdisplay/Kconfig
@@ -489,7 +489,7 @@ config IMG_ASCII_LCD
 
 config HT16K33
 	tristate "Holtek Ht16K33 LED controller with keyscan"
-	depends on FB && I2C && INPUT
+	depends on FB && I2C && INPUT && BACKLIGHT_CLASS_DEVICE
 	select FB_SYSMEM_HELPERS
 	select INPUT_MATRIXKMAP
 	select FB_BACKLIGHT
diff --git a/drivers/macintosh/Kconfig b/drivers/macintosh/Kconfig
index fb38f684444f..bf3824032d61 100644
--- a/drivers/macintosh/Kconfig
+++ b/drivers/macintosh/Kconfig
@@ -120,6 +120,7 @@ config PMAC_MEDIABAY
 config PMAC_BACKLIGHT
 	bool "Backlight control for LCD screens"
 	depends on PPC_PMAC && ADB_PMU && FB = y && (BROKEN || !PPC64)
+	depends on BACKLIGHT_CLASS_DEVICE
 	select FB_BACKLIGHT
 	help
 	  Say Y here to enable Macintosh specific extensions of the generic
diff --git a/drivers/staging/fbtft/Kconfig b/drivers/staging/fbtft/Kconfig
index 77ab44362f16..dcf6a70455cc 100644
--- a/drivers/staging/fbtft/Kconfig
+++ b/drivers/staging/fbtft/Kconfig
@@ -3,6 +3,7 @@ menuconfig FB_TFT
 	tristate "Support for small TFT LCD display modules"
 	depends on FB && SPI
 	depends on FB_DEVICE
+	depends on BACKLIGHT_CLASS_DEVICE
 	depends on GPIOLIB || COMPILE_TEST
 	select FB_BACKLIGHT
 	select FB_SYSMEM_HELPERS_DEFERRED
diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
index de035071fedb..55c6686f091e 100644
--- a/drivers/video/fbdev/Kconfig
+++ b/drivers/video/fbdev/Kconfig
@@ -649,6 +649,7 @@ config FB_S1D13XXX
 config FB_ATMEL
 	tristate "AT91 LCD Controller support"
 	depends on FB && OF && HAVE_CLK && HAS_IOMEM
+	depends on BACKLIGHT_CLASS_DEVICE
 	depends on HAVE_FB_ATMEL || COMPILE_TEST
 	select FB_BACKLIGHT
 	select FB_IOMEM_HELPERS
@@ -660,7 +661,6 @@ config FB_ATMEL
 config FB_NVIDIA
 	tristate "nVidia Framebuffer Support"
 	depends on FB && PCI
-	select FB_BACKLIGHT if FB_NVIDIA_BACKLIGHT
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
@@ -700,6 +700,8 @@ config FB_NVIDIA_DEBUG
 config FB_NVIDIA_BACKLIGHT
 	bool "Support for backlight control"
 	depends on FB_NVIDIA
+	depends on BACKLIGHT_CLASS_DEVICE=y || BACKLIGHT_CLASS_DEVICE=FB_NVIDIA
+	select FB_BACKLIGHT
 	default y
 	help
 	  Say Y here if you want to control the backlight of your display.
@@ -707,7 +709,6 @@ config FB_NVIDIA_BACKLIGHT
 config FB_RIVA
 	tristate "nVidia Riva support"
 	depends on FB && PCI
-	select FB_BACKLIGHT if FB_RIVA_BACKLIGHT
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
@@ -747,6 +748,8 @@ config FB_RIVA_DEBUG
 config FB_RIVA_BACKLIGHT
 	bool "Support for backlight control"
 	depends on FB_RIVA
+	depends on BACKLIGHT_CLASS_DEVICE=y || BACKLIGHT_CLASS_DEVICE=FB_RIVA
+	select FB_BACKLIGHT
 	default y
 	help
 	  Say Y here if you want to control the backlight of your display.
@@ -934,7 +937,6 @@ config FB_MATROX_MAVEN
 config FB_RADEON
 	tristate "ATI Radeon display support"
 	depends on FB && PCI
-	select FB_BACKLIGHT if FB_RADEON_BACKLIGHT
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
@@ -960,6 +962,8 @@ config FB_RADEON_I2C
 config FB_RADEON_BACKLIGHT
 	bool "Support for backlight control"
 	depends on FB_RADEON
+	depends on BACKLIGHT_CLASS_DEVICE=y || BACKLIGHT_CLASS_DEVICE=FB_RADEON
+	select FB_BACKLIGHT
 	default y
 	help
 	  Say Y here if you want to control the backlight of your display.
@@ -975,7 +979,6 @@ config FB_RADEON_DEBUG
 config FB_ATY128
 	tristate "ATI Rage128 display support"
 	depends on FB && PCI
-	select FB_BACKLIGHT if FB_ATY128_BACKLIGHT
 	select FB_IOMEM_HELPERS
 	select FB_MACMODES if PPC_PMAC
 	help
@@ -989,6 +992,8 @@ config FB_ATY128
 config FB_ATY128_BACKLIGHT
 	bool "Support for backlight control"
 	depends on FB_ATY128
+	depends on BACKLIGHT_CLASS_DEVICE=y || BACKLIGHT_CLASS_DEVICE=FB_ATY128
+	select FB_BACKLIGHT
 	default y
 	help
 	  Say Y here if you want to control the backlight of your display.
@@ -999,7 +1004,6 @@ config FB_ATY
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
-	select FB_BACKLIGHT if FB_ATY_BACKLIGHT
 	select FB_IOMEM_FOPS
 	select FB_MACMODES if PPC
 	select FB_ATY_CT if SPARC64 && PCI
@@ -1040,6 +1044,8 @@ config FB_ATY_GX
 config FB_ATY_BACKLIGHT
 	bool "Support for backlight control"
 	depends on FB_ATY
+	depends on BACKLIGHT_CLASS_DEVICE=y || BACKLIGHT_CLASS_DEVICE=FB_ATY
+	select FB_BACKLIGHT
 	default y
 	help
 	  Say Y here if you want to control the backlight of your display.
@@ -1528,6 +1534,7 @@ config FB_SH_MOBILE_LCDC
 	depends on FB && HAVE_CLK && HAS_IOMEM
 	depends on SUPERH || COMPILE_TEST
 	depends on FB_DEVICE
+	depends on BACKLIGHT_CLASS_DEVICE
 	select FB_BACKLIGHT
 	select FB_DEFERRED_IO
 	select FB_DMAMEM_HELPERS
@@ -1793,6 +1800,7 @@ config FB_SSD1307
 	tristate "Solomon SSD1307 framebuffer support"
 	depends on FB && I2C
 	depends on GPIOLIB || COMPILE_TEST
+	depends on BACKLIGHT_CLASS_DEVICE
 	select FB_BACKLIGHT
 	select FB_SYSMEM_HELPERS_DEFERRED
 	help
diff --git a/drivers/video/fbdev/core/Kconfig b/drivers/video/fbdev/core/Kconfig
index 0ab8848ba2f1..d554d8c543d4 100644
--- a/drivers/video/fbdev/core/Kconfig
+++ b/drivers/video/fbdev/core/Kconfig
@@ -183,9 +183,8 @@ config FB_SYSMEM_HELPERS_DEFERRED
 	select FB_SYSMEM_HELPERS
 
 config FB_BACKLIGHT
-	tristate
+	bool
 	depends on FB
-	select BACKLIGHT_CLASS_DEVICE
 
 config FB_MODE_HELPERS
 	bool "Enable Video Mode Handling Helpers"
-- 
2.47.1

