drm/rockchip: cancel pending vblanks on close

Browse source

When closing the DRM device while a vblank is pending, we access
file_priv after it has been free'd, which gives:

  Unable to handle kernel NULL pointer dereference at virtual address 00000000
  ...
  PC is at __list_add+0x5c/0xe8
  LR is at send_vblank_event+0x54/0x1f0
  ...
  [<c02952e8>] (__list_add) from [<c031a7b4>] (send_vblank_event+0x54/0x1f0)
  [<c031a760>] (send_vblank_event) from [<c031a9c0>] (drm_send_vblank_event+0x70/0x78)
  [<c031a950>] (drm_send_vblank_event) from [<c031a9f8>] (drm_crtc_send_vblank_event+0x30/0x34)
  [<c031a9c8>] (drm_crtc_send_vblank_event) from [<c0339ad8>] (vop_isr+0x224/0x28c)
  [<c03398b4>] (vop_isr) from [<c0081780>] (handle_irq_event_percpu+0x12c/0x3e4)

This can be triggered somewhat reliably with:

	modetest -M rockchip -v -s ...

Add a preclose hook to the driver so that we can discard any pending
vblank events when the device is closed.

Signed-off-by: John Keeping <john@metanate.com>

...

This commit is contained in:

John Keeping 2016-03-11 17:21:17 +00:00 • committed by Mark Yao

parent 92915da647

commit f135046e51

3 changed files with 43 additions and 0 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

22

drivers/gpu/drm/rockchip/rockchip_drm_drv.c

View file

1

drivers/gpu/drm/rockchip/rockchip_drm_drv.h

View file

20

drivers/gpu/drm/rockchip/rockchip_drm_vop.c

View file