[PATCH v1 0/3] media: sun4i-csi: fix lifecycle bugs (leak, IRQ, unbind)

[Cong Nguyen]

While addressing an async-notifier cleanup leak in this driver, I audited
the surrounding device lifecycle and found three separate pre-existing
issues, all present since the driver was introduced. They are independent
of each other; this series groups them because they touch the same driver.

1/3: sun4i_csi_notify_complete() registers the video device and the bridge
     subdev before creating the media links. On a failure in the later
     steps it only unregistered the media device, leaving /dev/videoX
     registered. Since probe then aborts and the devm-managed context
     (embedding the video_device) is freed, an open() would touch freed
     memory. Unwind the registrations in reverse order.

2/3: sun4i_csi_stop_streaming() stops the capture engine but never disables
     the frame-done interrupt or synchronizes with the handler. A late IRQ
     after the block is runtime-suspended (on release) can access gated
     registers and crash. Clear CSI_INT_EN_REG and synchronize_irq().

3/3: The async notifier ops lack an .unbind callback, so csi->src_subdev is
     left dangling when the remote sensor is unbound; a later STREAMON
     dereferences the freed subdev. Add .unbind to unregister the video
     device and clear the pointer, matching stm32-dcmi/atmel-isi/mcam.

All three are marked for stable. Compile-tested (COMPILE_TEST) and
checkpatch --strict clean. I do not have the hardware, so testing on a
real A10/A20 CSI setup would be appreciated.

Cong Nguyen (3):
  media: sun4i-csi: fix video device and subdev leak in
    notify_complete()
  media: sun4i-csi: disable interrupts when stopping streaming
  media: sun4i-csi: add notifier unbind callback to drop the source
    subdev

 .../platform/sunxi/sun4i-csi/sun4i_csi.c      | 25 +++++++++++++++++--
 .../platform/sunxi/sun4i-csi/sun4i_csi.h      |  1 +
 .../platform/sunxi/sun4i-csi/sun4i_dma.c      | 11 ++++++++
 3 files changed, 35 insertions(+), 2 deletions(-)

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2.25.1