Hi


Am 13.12.24 um 08:44 schrieb Christophe Leroy:

Le 12/12/2024 à 11:04, Thomas Zimmermann a écrit :

quoted

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@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(-)

Build fails which pmac32_defconfig :

  LD      .tmp_vmlinux1
powerpc64-linux-ld: drivers/macintosh/via-pmu-backlight.o: in function 
`pmu_backlight_init':
via-pmu-backlight.c:(.init.text+0xc0): undefined reference to 
`backlight_device_register'
make[2]: *** [scripts/Makefile.vmlinux:77: vmlinux] Error 1
make[1]: *** [/home/chleroy/linux-powerpc/Makefile:1225: vmlinux] Error 2

The attached patch selects backlight support in the defconfigs that also 
have PMAC_BACKLIGHT=y. Can you please apply it on top of the patchset 
and report on the results?

Best regards
Thomas

quoted

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"

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)