Hi
Am 22.12.24 um 07:31 schrieb Helge Deller:
On 12/16/24 08:42, 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.
v3:
- Select BACKLIGHT_CLASS_DEVICE in PowerMac defconfigs (Christophe)
- Fix PMAC_BACKLIGHT module dependency corner cases (Christophe)
v2:
- s/BACKLIGHT_DEVICE_CLASS/BACKLIGHT_CLASS_DEVICE (Helge)
- Fix fbdev driver-dependency corner case (Arnd)
Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
---
arch/powerpc/configs/pmac32_defconfig | 1 +
arch/powerpc/configs/ppc6xx_defconfig | 1 +
drivers/auxdisplay/Kconfig | 2 +-
drivers/macintosh/Kconfig | 1 +
drivers/staging/fbtft/Kconfig | 1 +
drivers/video/fbdev/Kconfig | 18 +++++++++++++-----
drivers/video/fbdev/core/Kconfig | 3 +--
7 files changed, 19 insertions(+), 8 deletions(-)
...
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
Seems wrong. BACKLIGHT_CLASS_DEVICE is of type tristate.
There are more of those, please check.
It's exactly correct. Linking would fail with FB_NVIDIA=y and
BACKLIGHT=m. The above construct avoids this case. Please see Arnd's
review comment at [1].
That's also why I mentioned that 'imply' could be used rather than
'depends on'. It would handle this situation automatically.
Best regards
Thomas
[1] https://patchwork.freedesktop.org/patch/628099/?series=142356&rev=1
Helge
--
--
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)
