[0/5] sysfb: Fix memory-region management

Message

Thomas Zimmermann Jan. 24, 2022, 12:36 p.m. UTC

Request framebuffer memory in simpledrm and simplefb. Do a hot-unplug
operation when removing fbdev firmware drivers.

After being unloaded by a hardware driver, simplefb leaves behind the
firmware framebuffer's platform device. This prevents other drivers
from acquiring the memory as reported at [1].

Patch 1 changes the removal code of remove_conflicting_framebuffers()
to remove the underlying device and the rsp memory region.

Patches 2 to 4 update sysfb and its drivers. The sysfb code does no
longer mark the framebuffer memory with IORESOURCE_BUSY. Instead, the
device drivers acquire the memory when they probe the device.

Patch 5 adds a todo item to acquire memory regions in all DRM drivers.

Tested with simpledrm and simplefb.

[1] https://lore.kernel.org/dri-devel/[e-mail]/

Javier Martinez Canillas (1):
  drivers/firmware: Don't mark as busy the simple-framebuffer IO
    resource

Thomas Zimmermann (4):
  fbdev: Hot-unplug firmware fb devices on forced removal
  drm/simpledrm: Request memory region in driver
  fbdev/simplefb: Request memory region in driver
  drm: Add TODO item for requesting memory regions

 Documentation/gpu/todo.rst        | 15 ++++++++
 drivers/firmware/sysfb_simplefb.c |  2 +-
 drivers/gpu/drm/tiny/simpledrm.c  | 20 ++++++++---
 drivers/video/fbdev/core/fbmem.c  | 29 +++++++++++++--
 drivers/video/fbdev/simplefb.c    | 59 ++++++++++++++++++++++---------
 include/linux/fb.h                |  1 +
 6 files changed, 100 insertions(+), 26 deletions(-)


base-commit: 0bb81b5d6db5f689b67f9d8b35323235c45e890f