On 12/12/24 11:04, Thomas Zimmermann wrote:
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 [...]
I think in the fbdev drivers themselves you should do:
select BACKLIGHT_CLASS_DEVICE
instead of "depending" on it.
This is the way as it's done in the DRM tiny and the i915/gma500 DRM drivers.
So, something like:
--- a/drivers/staging/fbtft/Kconfig
tristate "Support for small TFT LCD display modules"
depends on FB && SPI
depends on FB_DEVICE
+ select BACKLIGHT_DEVICE_CLASS
depends on GPIOLIB || COMPILE_TEST
select FB_BACKLIGHT
config FB_BACKLIGHT
tristate
depends on FB
- select BACKLIGHT_CLASS_DEVICE
+ depends on BACKLIGHT_CLASS_DEVICE
Would that fix the dependency warning?
Helge
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@xxxxxxx>
---
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"
