Arnd Bergmann
c40ca9ef7c
In the combination of DRM_KMS_HELPER=m, DRM_GEM_SHMEM_HELPER=y, DRM_FBDEV_EMULATION=y, The shmem code fails to link against the KMS helpers: x86_64-linux-ld: vmlinux.o: in function `drm_fbdev_shmem_driver_fbdev_probe': (.text+0xeec601): undefined reference to `drm_fb_helper_alloc_info' x86_64-linux-ld: (.text+0xeec633): undefined reference to `drm_fb_helper_fill_info' x86_64-linux-ld: vmlinux.o: in function `drm_fbdev_shmem_get_page': drm_fbdev_shmem.c:(.text+0xeec7d2): undefined reference to `drm_gem_fb_get_obj' x86_64-linux-ld: vmlinux.o: in function `drm_fbdev_shmem_fb_mmap': drm_fbdev_shmem.c:(.text+0xeec9f6): undefined reference to `drm_gem_fb_get_obj' x86_64-linux-ld: vmlinux.o: in function `drm_fbdev_shmem_defio_imageblit': (.rodata+0x5b2288): undefined reference to `drm_fb_helper_check_var' x86_64-linux-ld: (.rodata+0x5b2290): undefined reference to `drm_fb_helper_set_par' This can happen for a number of device drivers that select DRM_GEM_SHMEM_HELPER without also selecting DRM_KMS_HELPER. To work around this, add another select that forces DRM_KMS_HELPER to be built-in rather than a loadable module, but only if FBDEV emulation is also enabled. DRM_TTM_HELPER and DRM_GEM_DMA_HELPER look like they have the same problem in theory even if there is no possible configuration that shows it. For consistency, do the same change to those. Closes: https://lore.kernel.org/all/20250121-greedy-flounder-of-abundance-4d2ee8-mkl@pengutronix.de Reported-by: Marc Kleine-Budde <mkl@pengutronix.de> Tested-by: Marc Kleine-Budde <mkl@pengutronix.de> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20250122090211.3161186-1-arnd@kernel.org
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.