Hi
Am 16.03.22 um 19:36 schrieb Arnd Bergmann:
From: Arnd Bergmann <arnd@xxxxxxxx>
The driver fails to build when the KMS helpers are disabled:
ld.lld: error: undefined symbol: drm_gem_fb_get_obj
referenced by drm_mipi_dbi.c
gpu/drm/drm_mipi_dbi.o:(mipi_dbi_buf_copy) in archive drivers/built-in.a
referenced by drm_mipi_dbi.c
gpu/drm/drm_mipi_dbi.o:(mipi_dbi_fb_dirty) in archive drivers/built-in.a
ld.lld: error: undefined symbol: drm_gem_fb_begin_cpu_access
referenced by drm_mipi_dbi.c
gpu/drm/drm_mipi_dbi.o:(mipi_dbi_buf_copy) in archive drivers/built-in.a
ld.lld: error: undefined symbol: drm_fb_swab
referenced by drm_mipi_dbi.c
gpu/drm/drm_mipi_dbi.o:(mipi_dbi_buf_copy) in archive drivers/built-in.a
ld.lld: error: undefined symbol: drm_fb_xrgb8888_to_rgb565
referenced by drm_mipi_dbi.c
gpu/drm/drm_mipi_dbi.o:(mipi_dbi_buf_copy) in archive drivers/built-in.a
ld.lld: error: undefined symbol: drm_fb_memcpy
referenced by drm_mipi_dbi.c
gpu/drm/drm_mipi_dbi.o:(mipi_dbi_buf_copy) in archive drivers/built-in.a
This is fairly hard to hit in randconfig drivers, but it eventually
did trigger for me in a configuration where all other DRM drivers
are loadable modules, but DRM_PANEL_WIDECHIPS_WS2401 was built-in.
Adding a dependency in all drivers that select DRM_MIPI_DBI avoids
the problem for now, adding the dependency in DRM_MIPI_DBI as well
should help make it easier to figure out why it breaks if someone
forgets the dependency the next time.
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/gpu/drm/Kconfig | 2 +-
drivers/gpu/drm/panel/Kconfig | 4 ++++
2 files changed, 5 insertions(+), 1 deletion(-)
I see this warning on 5.17-rc8, but did not test it on linux-next,
which may already have a fix.
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index b1f22e457fd0..d5ec0b77c010 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -30,7 +30,7 @@ menuconfig DRM
config DRM_MIPI_DBI
tristate
- depends on DRM
+ depends on DRM_KMS_HELPER
This symbol cannot be selected by users, so it's maybe not a good idea to depend on it. In fact, I've had to remove such a statement because it created a cyclic dependency. [1]
Making the drivers depend on KMS helpers is the right thing though. If there's a better solution, please let me know.
Best regards
Thomas
config DRM_MIPI_DSI
bool
diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index 0aec5a10b064..96887d0efb9f 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -425,6 +425,7 @@ config DRM_PANEL_SAMSUNG_DB7430
tristate "Samsung DB7430-based DPI panels"
depends on OF && SPI && GPIOLIB
depends on BACKLIGHT_CLASS_DEVICE
+ depends on DRM_KMS_HELPER
select DRM_MIPI_DBI
help
Say Y here if you want to enable support for the Samsung
@@ -440,6 +441,7 @@ config DRM_PANEL_SAMSUNG_S6D16D0
config DRM_PANEL_SAMSUNG_S6D27A1
tristate "Samsung S6D27A1 DPI panel driver"
depends on OF && SPI && GPIOLIB
+ depends on DRM_KMS_HELPER
select DRM_MIPI_DBI
help
Say Y here if you want to enable support for the Samsung
@@ -476,6 +478,7 @@ config DRM_PANEL_SAMSUNG_S6E63M0_SPI
depends on SPI
depends on DRM_PANEL_SAMSUNG_S6E63M0
default DRM_PANEL_SAMSUNG_S6E63M0
+ depends on DRM_KMS_HELPER
select DRM_MIPI_DBI
help
Say Y here if you want to be able to access the Samsung
@@ -677,6 +680,7 @@ config DRM_PANEL_WIDECHIPS_WS2401
tristate "Widechips WS2401 DPI panel driver"
depends on SPI && GPIOLIB
depends on BACKLIGHT_CLASS_DEVICE
+ depends on DRM_KMS_HELPER
select DRM_MIPI_DBI
help
Say Y here if you want to enable support for the Widechips WS2401 DPI
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