| Message ID | 20241210142329.660801-2-tzimmermann@suse.de |
|---|---|
| State | Superseded |
| Headers | show |
| Series | drm,fbdev: Fix module dependencies | expand |
On 12/10/24 15:09, Thomas Zimmermann wrote: > diff --git a/drivers/staging/fbtft/Kconfig b/drivers/staging/fbtft/Kconfig > index 77ab44362f16..577e91ff7bf6 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_DEVICE_CLASS Typo. Should be BACKLIGHT_CLASS_DEVICE... Helge
On Tue, Dec 10, 2024, at 15:09, 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 > > 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. > > Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Thanks for revisiting this! My patch that failed to work correctly happened to work on my randconfig tree because I still have an old variant of this change, see https://lore.kernel.org/linux-fbdev/20200417155553.675905-8-arnd@arndb.de/ This is almost the same as your version, except for the optional fbdev Kconfig bits PERS > @@ -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 > + select FB_BACKLIGHT > default y > help > Say Y here if you want to control the backlight of your display. For instance here I used @@ -702,6 +703,7 @@ 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 default y help Say Y here if you want to control the backlight of your display. while your patch causes a link failure with CONFIG_FB_NVIDIA=y CONFIG_FB_NVIDIA_BACKLIGHT=y CONFIG_BACKLIGHT_CLASS_DEVICE=m Arnd
On 12/10/24 15:29, Helge Deller wrote: > On 12/10/24 15:09, Thomas Zimmermann wrote: >> diff --git a/drivers/staging/fbtft/Kconfig b/drivers/staging/fbtft/Kconfig >> index 77ab44362f16..577e91ff7bf6 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_DEVICE_CLASS > > Typo. Should be BACKLIGHT_CLASS_DEVICE... Beside the typo: In this case, doesn't it make sense to "select BACKLIGHT_DEVICE_CLASS" instead? If people want the fbtft, backlight support should be enabled too. Helge
Hi Am 10.12.24 um 15:34 schrieb Helge Deller: > On 12/10/24 15:29, Helge Deller wrote: >> On 12/10/24 15:09, Thomas Zimmermann wrote: >>> diff --git a/drivers/staging/fbtft/Kconfig >>> b/drivers/staging/fbtft/Kconfig >>> index 77ab44362f16..577e91ff7bf6 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_DEVICE_CLASS >> >> Typo. Should be BACKLIGHT_CLASS_DEVICE... Ah, thanks. I'll better check the rest of the series for similar mistakes. > > Beside the typo: > In this case, doesn't it make sense to "select BACKLIGHT_DEVICE_CLASS" > instead? That causes the dependency error mentioned in the commit message. This time it's just for fbtft instead of shmobilefb. > If people want the fbtft, backlight support should be enabled too. As a user-visible option, it should not be auto-selected unnecessarily. The DRM panel drivers already depend on the backlight instead of selecting it. It's the correct approach. As I mentioned in the cover letter, the few remaining driver that select it should probably be updated. Best regards Thomas > > Helge >
Hi Am 10.12.24 um 15:30 schrieb Arnd Bergmann: > On Tue, Dec 10, 2024, at 15:09, 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 >> >> 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. >> >> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> > Thanks for revisiting this! > > My patch that failed to work correctly happened to work on my > randconfig tree because I still have an old variant of this > change, see > > https://lore.kernel.org/linux-fbdev/20200417155553.675905-8-arnd@arndb.de/ > > This is almost the same as your version, except for the > optional fbdev Kconfig bits > PERS >> @@ -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 >> + select FB_BACKLIGHT >> default y >> help >> Say Y here if you want to control the backlight of your display. > For instance here I used > > @@ -702,6 +703,7 @@ 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 > default y > help > Say Y here if you want to control the backlight of your display. > > while your patch causes a link failure with > > CONFIG_FB_NVIDIA=y > CONFIG_FB_NVIDIA_BACKLIGHT=y > CONFIG_BACKLIGHT_CLASS_DEVICE=m Ah, right. I'll update the series to use your approach. Best regards Thomas > > Arnd
On 12/10/24 16:41, Thomas Zimmermann wrote: > Hi > > > Am 10.12.24 um 15:34 schrieb Helge Deller: >> On 12/10/24 15:29, Helge Deller wrote: >>> On 12/10/24 15:09, Thomas Zimmermann wrote: >>>> diff --git a/drivers/staging/fbtft/Kconfig b/drivers/staging/fbtft/Kconfig >>>> index 77ab44362f16..577e91ff7bf6 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_DEVICE_CLASS >>> >>> Typo. Should be BACKLIGHT_CLASS_DEVICE... > > Ah, thanks. I'll better check the rest of the series for similar mistakes. > >> >> Beside the typo: >> In this case, doesn't it make sense to "select BACKLIGHT_DEVICE_CLASS" instead? > > That causes the dependency error mentioned in the commit message. This time it's just for fbtft instead of shmobilefb. > >> If people want the fbtft, backlight support should be enabled too. > > As a user-visible option, it should not be auto-selected > unnecessarily. Right, it should not be auto-selected. Unless if fbtft really needs it enabled to function. IMHO all fb/drm drivers have higher priority than some low-level background backlight controller code. > The DRM panel drivers already depend on the backlight > instead of selecting it. It's the correct approach. Sounds wrong IMHO. > As I mentioned > in the cover letter, the few remaining driver that select it should > probably be updated. That dependency sounds weird, but maybe I simply misunderstand your logic...? As a Linux end user I usually know which graphic cards are in my machine and which ones I want to enable. But as a normal user I think I shouldn't be expected to know that I first need to enable the "backlight class device" so that I'm then able to afterwards enable the fbtft (or any other drm/fb driver). Am I wrong? Helge
On 12/11/24 00:37, Helge Deller wrote: > On 12/10/24 16:41, Thomas Zimmermann wrote: >> Hi >> >> >> Am 10.12.24 um 15:34 schrieb Helge Deller: >>> On 12/10/24 15:29, Helge Deller wrote: >>>> On 12/10/24 15:09, Thomas Zimmermann wrote: >>>>> diff --git a/drivers/staging/fbtft/Kconfig b/drivers/staging/fbtft/Kconfig >>>>> index 77ab44362f16..577e91ff7bf6 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_DEVICE_CLASS >>>> >>>> Typo. Should be BACKLIGHT_CLASS_DEVICE... >> >> Ah, thanks. I'll better check the rest of the series for similar mistakes. >> >>> >>> Beside the typo: >>> In this case, doesn't it make sense to "select BACKLIGHT_DEVICE_CLASS" instead? >> >> That causes the dependency error mentioned in the commit message. This time it's just for fbtft instead of shmobilefb. >> >>> If people want the fbtft, backlight support should be enabled too. >> >> As a user-visible option, it should not be auto-selected >> unnecessarily. > > Right, it should not be auto-selected. > Unless if fbtft really needs it enabled to function. > IMHO all fb/drm drivers have higher priority than some low-level > background backlight controller code. > >> The DRM panel drivers already depend on the backlight >> instead of selecting it. It's the correct approach. > > Sounds wrong IMHO. > >> As I mentioned >> in the cover letter, the few remaining driver that select it should >> probably be updated. > > That dependency sounds weird, but maybe I simply misunderstand your logic...? > > As a Linux end user I usually know which graphic cards are in my machine > and which ones I want to enable. > But as a normal user I think I shouldn't be expected to know > that I first need to enable the "backlight class device" > so that I'm then able to afterwards enable the fbtft (or any other drm/fb driver). > > Am I wrong? Looking closer on this... You propose: --- 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_DEVICE_CLASS depends on GPIOLIB || COMPILE_TEST select FB_BACKLIGHT So, it will depend on BACKLIGHT_DEVICE_CLASS. But there is "select FB_BACKLIGHT" as well, which is: config FB_BACKLIGHT tristate depends on FB select BACKLIGHT_CLASS_DEVICE So, you end up with selecting and depending on BACKLIGHT_CLASS_DEVICE ? Helge
On 12/11/24 00:53, Helge Deller wrote: > On 12/11/24 00:37, Helge Deller wrote: >> On 12/10/24 16:41, Thomas Zimmermann wrote: >>> Hi >>> >>> >>> Am 10.12.24 um 15:34 schrieb Helge Deller: >>>> On 12/10/24 15:29, Helge Deller wrote: >>>>> On 12/10/24 15:09, Thomas Zimmermann wrote: >>>>>> diff --git a/drivers/staging/fbtft/Kconfig b/drivers/staging/fbtft/Kconfig >>>>>> index 77ab44362f16..577e91ff7bf6 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_DEVICE_CLASS >>>>> >>>>> Typo. Should be BACKLIGHT_CLASS_DEVICE... >>> >>> Ah, thanks. I'll better check the rest of the series for similar mistakes. >>> >>>> >>>> Beside the typo: >>>> In this case, doesn't it make sense to "select BACKLIGHT_DEVICE_CLASS" instead? >>> >>> That causes the dependency error mentioned in the commit message. This time it's just for fbtft instead of shmobilefb. >>> >>>> If people want the fbtft, backlight support should be enabled too. >>> >>> As a user-visible option, it should not be auto-selected >>> unnecessarily. >> >> Right, it should not be auto-selected. >> Unless if fbtft really needs it enabled to function. >> IMHO all fb/drm drivers have higher priority than some low-level >> background backlight controller code. >> >>> The DRM panel drivers already depend on the backlight >>> instead of selecting it. It's the correct approach. >> >> Sounds wrong IMHO. >> >>> As I mentioned >>> in the cover letter, the few remaining driver that select it should >>> probably be updated. >> >> That dependency sounds weird, but maybe I simply misunderstand your logic...? >> >> As a Linux end user I usually know which graphic cards are in my machine >> and which ones I want to enable. >> But as a normal user I think I shouldn't be expected to know >> that I first need to enable the "backlight class device" >> so that I'm then able to afterwards enable the fbtft (or any other drm/fb driver). >> >> Am I wrong? > > Looking closer on this... > You propose: > > --- 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_DEVICE_CLASS > depends on GPIOLIB || COMPILE_TEST > select FB_BACKLIGHT > > So, it will depend on BACKLIGHT_DEVICE_CLASS. > But there is "select FB_BACKLIGHT" as well, which is: > config FB_BACKLIGHT > tristate > depends on FB > select BACKLIGHT_CLASS_DEVICE > > So, you end up with selecting and depending on BACKLIGHT_CLASS_DEVICE ? Ok. Ignore this ^^^ . I now understand your cover letter. Looking at your DRM tiny drivers and the i915/gma500 DRM drivers, there is a "select BACKLIGHT_CLASS_DEVICE" in those. So, isn't the right approach then 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 + depends on BACKLIGHT_CLASS_DEVICE ?
Hi Am 11.12.24 um 00:37 schrieb Helge Deller: > On 12/10/24 16:41, Thomas Zimmermann wrote: >> Hi >> >> >> Am 10.12.24 um 15:34 schrieb Helge Deller: >>> On 12/10/24 15:29, Helge Deller wrote: >>>> On 12/10/24 15:09, Thomas Zimmermann wrote: >>>>> diff --git a/drivers/staging/fbtft/Kconfig >>>>> b/drivers/staging/fbtft/Kconfig >>>>> index 77ab44362f16..577e91ff7bf6 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_DEVICE_CLASS >>>> >>>> Typo. Should be BACKLIGHT_CLASS_DEVICE... >> >> Ah, thanks. I'll better check the rest of the series for similar >> mistakes. >> >>> >>> Beside the typo: >>> In this case, doesn't it make sense to "select >>> BACKLIGHT_DEVICE_CLASS" instead? >> >> That causes the dependency error mentioned in the commit message. >> This time it's just for fbtft instead of shmobilefb. >> >>> If people want the fbtft, backlight support should be enabled too. >> >> As a user-visible option, it should not be auto-selected >> unnecessarily. > > Right, it should not be auto-selected. > Unless if fbtft really needs it enabled to function. > IMHO all fb/drm drivers have higher priority than some low-level > background backlight controller code. By that logic, we'd list always list all drivers and each driver would auso-select the subsystems it requires. So each fbdev driver would select CONFIG_FB. That's not how it works, of course. Instead, each subsystem is user-selected and Kconfig offers the drivers that have their dependencies met. The documentation for Kconfig clearly states that select should be used carefully. [1] [1] https://elixir.bootlin.com/linux/v6.12.4/source/Documentation/kbuild/kconfig-language.rst#L137 > >> The DRM panel drivers already depend on the backlight >> instead of selecting it. It's the correct approach. > > Sounds wrong IMHO. Generally, it's the right approach. I guess what could be done is to make backlight support optional in the driver code, and use the imply attribute [2] instead of depends. So the driver would indicate a preference for backlight support, but still work without. That could also be done for the fbdev drivers, of course. [2] https://elixir.bootlin.com/linux/v6.12.4/source/Documentation/kbuild/kconfig-language.rst#L163 Best regards Thomas > >> As I mentioned >> in the cover letter, the few remaining driver that select it should >> probably be updated. > > That dependency sounds weird, but maybe I simply misunderstand your > logic...? > > As a Linux end user I usually know which graphic cards are in my machine > and which ones I want to enable. > But as a normal user I think I shouldn't be expected to know > that I first need to enable the "backlight class device" > so that I'm then able to afterwards enable the fbtft (or any other > drm/fb driver). > > Am I wrong? > > Helge
Hi Thomas, kernel test robot noticed the following build errors: [auto build test ERROR on staging/staging-testing] [also build test ERROR on staging/staging-next staging/staging-linus drm/drm-next drm-exynos/exynos-drm-next linus/master v6.13-rc2 next-20241211] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Thomas-Zimmermann/fbdev-Fix-recursive-dependencies-wrt-BACKLIGHT_CLASS_DEVICE/20241210-222618 base: staging/staging-testing patch link: https://lore.kernel.org/r/20241210142329.660801-2-tzimmermann%40suse.de patch subject: [PATCH 1/3] fbdev: Fix recursive dependencies wrt BACKLIGHT_CLASS_DEVICE config: loongarch-defconfig (https://download.01.org/0day-ci/archive/20241211/202412112135.pzFeIjEo-lkp@intel.com/config) compiler: loongarch64-linux-gcc (GCC) 14.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241211/202412112135.pzFeIjEo-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202412112135.pzFeIjEo-lkp@intel.com/ All errors (new ones prefixed by >>): loongarch64-linux-ld: drivers/video/fbdev/aty/radeon_backlight.o: in function `radeonfb_bl_init': >> radeon_backlight.c:(.text+0x424): undefined reference to `backlight_device_register' loongarch64-linux-ld: drivers/video/fbdev/aty/radeon_backlight.o: in function `radeonfb_bl_exit': >> radeon_backlight.c:(.text+0x560): undefined reference to `backlight_device_unregister'
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..577e91ff7bf6 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_DEVICE_CLASS 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..7f2f08748a27 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 + 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 + 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 + 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 + 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 + 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"
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. 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(-)