| Message ID | 20211117062704.14671-1-rdunlap@infradead.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/panel-edp: modify Kconfig to prevent build error | expand |
On Wed, Nov 17, 2021 at 7:27 AM Randy Dunlap <rdunlap@infradead.org> wrote: > > When CONFIG_DRM_KMS_HELPER=m and CONFIG_DRM_PANEL_EDP=y, > there is a build error in gpu/drm/panel/panel-edp.o: > > arm-linux-gnueabi-ld: drivers/gpu/drm/panel/panel-edp.o: in function `panel_edp_probe': > panel-edp.c:(.text+0xf38): undefined reference to `drm_panel_dp_aux_backlight' > > Fix this by limiting DRM_PANEL_DEP by the value of the DRM_KMS_HELPER > symbol. I think the analysis is correct, but this is not the correct fix since DRM_KMS_HELPER is not user-selectable. (Almost) all other drivers that rely on DRM_KMS_HELPER use 'select' for this, and mixing the two risks running into circular dependencies. I see that there are already some 'depends on DRM_KMS_HELPER' in bridge and panel drivers, so it's possible that we have to fix them all at the same to do this right. I ran into another problem like this the other day and I'm currently testing with the patch below, but I have not posted that yet since I am not fully convinced that this is the correct fix either. Arnd --- commit a836092fedaac66af03ea9ed7cb13214fd2ab8a2 Author: Arnd Bergmann <arnd@arndb.de> Date: Mon Nov 15 16:54:04 2021 +0100 drm/mipi-dbi: select CONFIG_DRM_KMS_HELPER 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. Signed-off-by: Arnd Bergmann <arnd@arndb.de> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index 0039df26854b..a03c2761c5f9 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -29,6 +29,7 @@ menuconfig DRM config DRM_MIPI_DBI tristate + select DRM_KMS_HELPER depends on DRM config DRM_MIPI_DSI diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig index 431b6e12a81f..17a8d603e7d8 100644 --- a/drivers/gpu/drm/bridge/Kconfig +++ b/drivers/gpu/drm/bridge/Kconfig @@ -8,7 +8,6 @@ config DRM_BRIDGE config DRM_PANEL_BRIDGE def_bool y depends on DRM_BRIDGE - depends on DRM_KMS_HELPER select DRM_PANEL help DRM bridge wrapper of DRM panels diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig index cfc8d644cedf..40ec20f3552d 100644 --- a/drivers/gpu/drm/panel/Kconfig +++ b/drivers/gpu/drm/panel/Kconfig @@ -140,9 +140,8 @@ config DRM_PANEL_ILITEK_IL9322 config DRM_PANEL_ILITEK_ILI9341 tristate "Ilitek ILI9341 240x320 QVGA panels" depends on OF && SPI - depends on DRM_KMS_HELPER - depends on DRM_KMS_CMA_HELPER depends on BACKLIGHT_CLASS_DEVICE + select DRM_KMS_CMA_HELPER select DRM_MIPI_DBI help Say Y here if you want to enable support for Ilitek IL9341
On 11/16/21 11:58 PM, Arnd Bergmann wrote: > On Wed, Nov 17, 2021 at 7:27 AM Randy Dunlap <rdunlap@infradead.org> wrote: >> >> When CONFIG_DRM_KMS_HELPER=m and CONFIG_DRM_PANEL_EDP=y, >> there is a build error in gpu/drm/panel/panel-edp.o: >> >> arm-linux-gnueabi-ld: drivers/gpu/drm/panel/panel-edp.o: in function `panel_edp_probe': >> panel-edp.c:(.text+0xf38): undefined reference to `drm_panel_dp_aux_backlight' >> >> Fix this by limiting DRM_PANEL_DEP by the value of the DRM_KMS_HELPER >> symbol. > > I think the analysis is correct, but this is not the correct fix since > DRM_KMS_HELPER > is not user-selectable. (Almost) all other drivers that rely on DRM_KMS_HELPER > use 'select' for this, and mixing the two risks running into circular > dependencies. Oops. Thanks for catching that. My first (local) version of the patch used select, but that got me into kconfig circular dependency chain land (ugly). Maybe your all-at-once patch can take care of that problem. > > I see that there are already some 'depends on DRM_KMS_HELPER' in bridge > and panel drivers, so it's possible that we have to fix them all at the same to > do this right. I ran into another problem like this the other day and > I'm currently > testing with the patch below, but I have not posted that yet since I am not > fully convinced that this is the correct fix either. I'll test some with it also. thanks.
--- linux-next-20211117.orig/drivers/gpu/drm/panel/Kconfig +++ linux-next-20211117/drivers/gpu/drm/panel/Kconfig @@ -104,6 +104,7 @@ config DRM_PANEL_EDP depends on OF depends on BACKLIGHT_CLASS_DEVICE depends on PM + depends on DRM_KMS_HELPER select VIDEOMODE_HELPERS select DRM_DP_AUX_BUS help
When CONFIG_DRM_KMS_HELPER=m and CONFIG_DRM_PANEL_EDP=y, there is a build error in gpu/drm/panel/panel-edp.o: arm-linux-gnueabi-ld: drivers/gpu/drm/panel/panel-edp.o: in function `panel_edp_probe': panel-edp.c:(.text+0xf38): undefined reference to `drm_panel_dp_aux_backlight' Fix this by limiting DRM_PANEL_DEP by the value of the DRM_KMS_HELPER symbol. Fixes: 5f04e7ce392d ("drm/panel-edp: Split eDP panels out of panel-simple") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: kernel test robot <lkp@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Javier Martinez Canillas <javierm@redhat.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Douglas Anderson <dianders@chromium.org> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: dri-devel@lists.freedesktop.org --- drivers/gpu/drm/panel/Kconfig | 1 + 1 file changed, 1 insertion(+)