Buildroot failed because of fbtft

[OmidID]

Hello,

I trying to build my custom kernel using buildroot for RPi3 and I get error that I cannot get rid of it.

In file included from drivers/video/fbdev/fbtft/fbtft-core.c:43:
drivers/video/fbdev/fbtft/fbtft.h:254:25: error: field ‘update_time’ has incomplete type
  254 |         struct timespec update_time;
      |                         ^~~~~~~~~~~
drivers/video/fbdev/fbtft/fbtft-core.c: In function ‘fbtft_update_display’:
drivers/video/fbdev/fbtft/fbtft-core.c:373:25: error: storage size of ‘ts_start’ isn’t known
  373 |         struct timespec ts_start, ts_end, ts_fps, ts_duration;
      |                         ^~~~~~~~
drivers/video/fbdev/fbtft/fbtft-core.c:373:35: error: storage size of ‘ts_end’ isn’t known
  373 |         struct timespec ts_start, ts_end, ts_fps, ts_duration;
      |                                   ^~~~~~
drivers/video/fbdev/fbtft/fbtft-core.c:373:43: error: storage size of ‘ts_fps’ isn’t known
  373 |         struct timespec ts_start, ts_end, ts_fps, ts_duration;
      |                                           ^~~~~~
drivers/video/fbdev/fbtft/fbtft-core.c:373:51: error: storage size of ‘ts_duration’ isn’t known
  373 |         struct timespec ts_start, ts_end, ts_fps, ts_duration;
      |                                                   ^~~~~~~~~~~
drivers/video/fbdev/fbtft/fbtft-core.c:382:25: error: implicit declaration of function ‘getnstimeofday’ [-Werror=implicit-function-declaration]
  382 |                         getnstimeofday(&ts_start);
      |                         ^~~~~~~~~~~~~~
drivers/video/fbdev/fbtft/fbtft-core.c:424:26: error: implicit declaration of function ‘timespec_sub’; did you mean ‘timespec64_sub’? [-Werror=implicit-function-declaration]
  424 |                 ts_fps = timespec_sub(ts_start, par->update_time);
      |                          ^~~~~~~~~~~~
      |                          timespec64_sub
drivers/video/fbdev/fbtft/fbtft-core.c:373:51: warning: unused variable ‘ts_duration’ [-Wunused-variable]
  373 |         struct timespec ts_start, ts_end, ts_fps, ts_duration;
      |                                                   ^~~~~~~~~~~
drivers/video/fbdev/fbtft/fbtft-core.c:373:43: warning: unused variable ‘ts_fps’ [-Wunused-variable]
  373 |         struct timespec ts_start, ts_end, ts_fps, ts_duration;
      |                                           ^~~~~~
drivers/video/fbdev/fbtft/fbtft-core.c:373:35: warning: unused variable ‘ts_end’ [-Wunused-variable]
  373 |         struct timespec ts_start, ts_end, ts_fps, ts_duration;
      |                                   ^~~~~~
drivers/video/fbdev/fbtft/fbtft-core.c:373:25: warning: unused variable ‘ts_start’ [-Wunused-variable]
  373 |         struct timespec ts_start, ts_end, ts_fps, ts_duration;
      |                         ^~~~~~~~
drivers/video/fbdev/fbtft/fbtft-core.c: In function ‘fbtft_unregister_framebuffer’:
drivers/video/fbdev/fbtft/fbtft-core.c:1053:13: error: void value not ignored as it ought to be
 1053 |         ret = unregister_framebuffer(fb_info);
      |             ^
cc1: some warnings being treated as errors
make[6]: *** [scripts/Makefile.build:280: drivers/video/fbdev/fbtft/fbtft-core.o] Error 1
make[5]: *** [scripts/Makefile.build:497: drivers/video/fbdev/fbtft] Error 2
make[5]: *** Waiting for unfinished jobs....

I also try to change the gcc to 11 but same error.

Any suggestion that I can fix this issue?

Thanks a lot. :)

[notro]

Are you enabling this option on a >=4.0 kernel?

config BR2_LINUX_KERNEL_EXT_FBTFT
    bool "FB TFT drivers"
    select BR2_PACKAGE_FBTFT
    help
      Linux Framebuffer drivers for small TFT LCD display modules,
      e.g. Adafruit PiTFT displays for Raspberry Pi (this extra
      package is only needed for linux kernels until v3.19, since
      v4.0 the drivers are included in the staging area).

If so that's your problem.

[OmidID]

Hello @notro . thanks for the answer. Yes, that is enabled

[notro]

Unless you use an old kernel you need to disable that.

[OmidID]

I using 5.17 . Actually, I tried both, disabled and enabled. the result will be the same :( Is there any flag or something that I must set to the gcc? Currently, I using gcc 11.

[notro]

fbtft doesn't use struct timespec in 5.17, it uses ktime_t so I don't know how you can get the same compile error: https://elixir.bootlin.com/linux/v5.17/source/drivers/staging/fbtft/fbtft.h#L228

[OmidID]

YOU RIGHT!!! I confused. How did I end up with this problem! :D Maybe something is wrong with the Buildroot. Do you have any idea what can check?

[notro]

If you disable the config option but doesn't clean the builddir, the driver stays around and you keep getting the error. The buildroot dependency system doesn't detect things like this.

[OmidID]

I did clean before each make run. each time I waited for 1-2 hours.

[github-actions[bot]]

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