Hi Thomas,
url:
https://github.com/intel-lab-lkp/linux/commits/Thomas-Zimmermann/fbdev-Decouple-deferred-I-O-from-struct-page/20220426-200655
base: 0e7deff6446a4ba2c75f499a0bfa80cd6a15c129
config: i386-randconfig-m021
(https://download.01.org/0day-ci/archive/20220428/202204280832.sghcydgq-.
The fbdev mmap function fb_mmap() unconditionally overrides the
driver's implementation if deferred I/O has been activated. This
makes it hard to implement mmap with anything but a vmalloc()'ed
software buffer. That is specifically a problem for DRM, where
video memory is maintained by a memory man
