Re: [PATCH v2 1/3] fbdev: Fix recursive dependencies wrt BACKLIGHT_CLASS_DEVICE
From: Helge Deller <deller@gmx.de>
Date: 2024-12-12 18:44:20
Also in:
dri-devel, linux-fbdev, linux-staging
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
quoted hunk ↗ jump to hunk
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@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_BACKLIGHTdiff --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 genericdiff --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_DEFERREDdiff --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 helpdiff --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"