Re: [PATCH] drm/panel: add CONFIG_DRM_KMS_HELPER dependencies

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 





Am 16.03.22 um 20:12 schrieb Thomas Zimmermann:
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]

[1] https://lore.kernel.org/dri-devel/20220315084559.23510-1-tzimmermann@xxxxxxx/


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


--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev

Attachment: OpenPGP_signature
Description: OpenPGP digital signature


[Index of Archives]     [Linux DRI Users]     [Linux Intel Graphics]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux