[5.10 Branch] Conflicting types for ms912x_fb_send_rect

[luizlinux]

I'm really puzzled by this:

/home/luiz/Downloads/ms912x-kernel-5.10/ms912x_transfer.c:185:5: error: conflicting types for ‘ms912x_fb_send_rect’
  185 | int ms912x_fb_send_rect(struct drm_framebuffer *fb, const struct iosys_map *map,
      |     ^~~~~~~~~~~~~~~~~~~
In file included from /home/luiz/Downloads/ms912x-kernel-5.10/ms912x_transfer.c:8:
/home/luiz/Downloads/ms912x-kernel-5.10/ms912x.h:113:5: note: previous declaration of ‘ms912x_fb_send_rect’ was here
  113 | int ms912x_fb_send_rect(struct drm_framebuffer *fb, const struct iosys_map *map,
      |     ^~~~~~~~~~~~~~~~~~~

The conflicting type error suggests that there might be a discrepancy between the declaration and definition of the ms912x_fb_send_rect functions, however they are identical. Any ideas what might be causing this?