[PATCH v3 0/1] media: atomisp: mt9m114: graceful teardown and reprobe fixes

From: Robert Mast

Date: Sun Apr 19 2026 - 11:26:39 EST


Hi,

this series addresses unload/reload instability between atomisp and mt9m114
seen on ACPI Bay Trail systems.

Problem summary:
- notifier lifecycle in atomisp could leave stale async state behind,
breaking subsequent probe/reprobe cycles
- mt9m114 remove path could race async unregister callback ordering
- reprobe after module cycling could fail or crash around endpoint/clock setup

This patch hardens teardown/probe behavior by:
- explicitly unregistering and cleaning atomisp async notifier state
- synchronizing mt9m114 async unregister via completion
- adding safer remove/shutdown handling in mt9m114
- making link-frequency control/validation robust when frequencies are absent
- using safe fallback clocking in the ACPI no-link-frequency path

Observed result on the test platform:
- repeated modprobe -r/modprobe cycles are stable
- no probe oops during the tested unload/reload loops

Changes in v3:
- clarify commit message around teardown/reprobe failure modes
- keep atomisp notifier cleanup in both normal teardown and parse error paths
- keep mt9m114 fallback clocking in the no-link-frequency ACPI path
- refresh cover letter with tested behavior summary

Changes in v2:
- initial split and hardening for atomisp notifier + mt9m114 teardown paths

Robert Mast (1):
media: atomisp: mt9m114: Graceful teardown atomisp and mt9m114

drivers/media/i2c/mt9m114.c | 118 ++++++++++++++++--
.../media/atomisp/pci/atomisp_csi2_bridge.c | 1 +
.../staging/media/atomisp/pci/atomisp_v4l2.c | 3 +
3 files changed, 110 insertions(+), 12 deletions(-)

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2.53.0