[PATCH 0/2] HID: picolcd: Fix output-request and framebuffer locking

This series fixes two PicoLCD locking problems. The first moves output
requests into sleepable context and serializes LED state updates. The
second breaks the last-close/deferred-worker lock dependency using a
private framebuffer update mutex.

The first patch was tested separately with the original syzkaller C
reproducer and bounded concurrent sysfs/UHID-destroy workloads on
PREEMPT_RT. The complete series additionally passed repeated framebuffer
open/write/close and persistent-open framebuffer tests. Pre-fix modules
reproduced the respective failures. Physical hardware, prolonged stress
and suspend/resume have not been tested.

Patch 2's Fixes tag identifies the fbdev change that began draining
deferred work from fb_release() while holding info->lock. Patch 1's Fixes
tag was checked against the upstream transport-conversion diff.

Aveline Noir (2):
  HID: picolcd: Move output requests out of spinlocked sections
  HID: picolcd: Avoid framebuffer last-close deadlock

 drivers/hid/hid-picolcd.h           |  4 +++
 drivers/hid/hid-picolcd_backlight.c |  7 ++--
 drivers/hid/hid-picolcd_core.c      | 46 +++++++++++++++---------
 drivers/hid/hid-picolcd_fb.c        | 56 ++++++++++++++++++-----------
 drivers/hid/hid-picolcd_lcd.c       |  7 ++--
 drivers/hid/hid-picolcd_leds.c      | 31 +++++++++-------
 6 files changed, 93 insertions(+), 58 deletions(-)


base-commit: 72d3fcf802c45d00b300f25b848a93c3a2bd7c7e
-- 
2.55.0