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| author | Robin Murphy <robin.murphy@arm.com> | 2016-11-24 17:40:50 +0300 |
|---|---|---|
| committer | Liviu Dudau <Liviu.Dudau@arm.com> | 2016-11-25 18:51:57 +0300 |
| commit | 747e5a5ff2a2ae84715c33d6679ac3c5220a3aec (patch) | |
| tree | 921ae9a39837f86ed72062dff64565a2034b2086 /drivers/gpu/drm/arm/hdlcd_drv.c | |
| parent | 7a79279e7186c4ac8b753cbd335ecc4ba81b5970 (diff) | |
| download | linux-747e5a5ff2a2ae84715c33d6679ac3c5220a3aec.tar.xz | |
drm: hdlcd: Fix cleanup order
If hdlcd_drm_bind() fails at drm_fbdev_cma_init(), its cleanup will call
drm_mode_config_cleanup() as if to balance drm_mode_config_reset(). The
net result is that drm_connector_cleanup() will clean up the active
connectors long before component_unbind_all() gets called, so when the
connector later tries to clean up itself after being unbound, Bad Things
can happen:
[ 4.121888] Unable to handle kernel NULL pointer dereference at
virtual address 00000000
[ 4.129951] pgd = ffffff80091e0000
[ 4.133345] [00000000] *pgd=00000009ffffe003, *pud=00000009ffffe003,
*pmd=0000000000000000
[ 4.141613] Internal error: Oops: 96000005 [#1] PREEMPT SMP
[ 4.147144] Modules linked in:
[ 4.150188] CPU: 0 PID: 122 Comm: kworker/u12:2 Not tainted
4.8.0-rc2+ #989
[ 4.157097] Hardware name: ARM Juno development board (r1) (DT)
[ 4.162981] Workqueue: deferwq deferred_probe_work_func
[ 4.168173] task: ffffffc975d93200 task.stack: ffffffc975dac000
[ 4.174055] PC is at drm_connector_cleanup+0x58/0x1c0
[ 4.179074] LR is at tda998x_unbind+0x24/0x40
[ 4.183401] pc : [<ffffff80084c46f0>] lr : [<ffffff800850414c>]
pstate: 00000045
[ 4.190750] sp : ffffffc975dafa10
[ 4.194041] x29: ffffffc975dafa10 x28: ffffffc9768152a8
[ 4.199325] x27: ffffffc97ff46450 x26: ffffff8008d99000
[ 4.204608] x25: dead000000000100 x24: dead000000000200
[ 4.209891] x23: ffffffc976bf91e8 x22: 0000000000000000
[ 4.215172] x21: ffffffc976bf9170 x20: ffffffc976bf9170
[ 4.220454] x19: ffffffc976bf9018 x18: 0000000000000000
[ 4.225737] x17: 0000000074ce71ee x16: 000000008ff5d35f
[ 4.231019] x15: ffffffc97681e91c x14: ffffffffffffffff
[ 4.236301] x13: ffffffc97681e185 x12: 0000000000000038
[ 4.241583] x11: 0101010101010101 x10: 0000000000000000
[ 4.246866] x9 : 0000000040000000 x8 : 0000000000210d00
[ 4.252148] x7 : ffffffc97fea8c00 x6 : 000000000000001b
[ 4.257430] x5 : ffffff80084b7b8c x4 : 0000000000000080
[ 4.262712] x3 : ffffff8008504128 x2 : ffffffc975df3800
[ 4.267993] x1 : 0000000000000000 x0 : 0000000000000000
...
[ 4.750937] [<ffffff80084c46f0>] drm_connector_cleanup+0x58/0x1c0
[ 4.756990] [<ffffff800850414c>] tda998x_unbind+0x24/0x40
[ 4.762354] [<ffffff8008507918>] component_unbind.isra.4+0x28/0x50
[ 4.768492] [<ffffff8008507a0c>] component_unbind_all+0xcc/0xd8
[ 4.774373] [<ffffff80084d5adc>] hdlcd_drm_bind+0x234/0x418
[ 4.779909] [<ffffff8008507b58>] try_to_bring_up_master+0x140/0x1a0
[ 4.786133] [<ffffff8008507c50>] component_add+0x98/0x170
[ 4.791496] [<ffffff8008504b90>] tda998x_probe+0x18/0x20
[ 4.796774] [<ffffff80086bf914>] i2c_device_probe+0x164/0x258
[ 4.802481] [<ffffff800850d094>] driver_probe_device+0x204/0x2b0
[ 4.808447] [<ffffff800850d28c>] __device_attach_driver+0x9c/0xf8
[ 4.814498] [<ffffff800850b108>] bus_for_each_drv+0x58/0x98
[ 4.820033] [<ffffff800850cd64>] __device_attach+0xc4/0x138
[ 4.825567] [<ffffff800850d338>] device_initial_probe+0x10/0x18
[ 4.831446] [<ffffff800850c124>] bus_probe_device+0x94/0xa0
[ 4.836981] [<ffffff800850c5b0>] deferred_probe_work_func+0x78/0xb0
[ 4.843207] [<ffffff80080d2998>] process_one_work+0x118/0x378
[ 4.848914] [<ffffff80080d2c40>] worker_thread+0x48/0x498
[ 4.854276] [<ffffff80080d8918>] kthread+0xd0/0xe8
[ 4.859036] [<ffffff8008082e90>] ret_from_fork+0x10/0x40
[ 4.864314] Code: f2fbd5b9 f2fbd5b8 f8478ee0 eb17001f (f9400013)
[ 4.870472] ---[ end trace a643cfe4ce1d838b ]---
Fix this by moving the drm_mode_config_cleanup() much later such that it
correctly balances drm_mode_config_init().
Suggested-by: Russell King <linux@armlinux.org.uk>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Diffstat (limited to 'drivers/gpu/drm/arm/hdlcd_drv.c')
| -rw-r--r-- | drivers/gpu/drm/arm/hdlcd_drv.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/gpu/drm/arm/hdlcd_drv.c b/drivers/gpu/drm/arm/hdlcd_drv.c index fb6a418ce6be..e138fb51e8ce 100644 --- a/drivers/gpu/drm/arm/hdlcd_drv.c +++ b/drivers/gpu/drm/arm/hdlcd_drv.c @@ -375,7 +375,6 @@ static int hdlcd_drm_bind(struct device *dev) err_fbdev: drm_kms_helper_poll_fini(drm); - drm_mode_config_cleanup(drm); drm_vblank_cleanup(drm); err_vblank: pm_runtime_disable(drm->dev); @@ -387,6 +386,7 @@ err_unload: drm_irq_uninstall(drm); of_reserved_mem_device_release(drm->dev); err_free: + drm_mode_config_cleanup(drm); dev_set_drvdata(dev, NULL); drm_dev_unref(drm); |