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 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 -- 2.29.2
