From: Alvin Šipraga <alsi@xxxxxxxxxxxxxxx>
cec_unregister_adapter() assumes that the underlying adapter ops are
callable. For example, if the CEC adapter currently has a valid physical
address, then the unregistration procedure will invalidate the physical
address by setting it to f.f.f.f. Whence the following kernel oops
observed after removing the adv7511 module:
Unable to handle kernel execution of user memory at virtual address 0000000000000000
Internal error: Oops: 86000004 [#1] PREEMPT_RT SMP
Call trace:
0x0
adv7511_cec_adap_log_addr+0x1ac/0x1c8 [adv7511]
cec_adap_unconfigure+0x44/0x90 [cec]
__cec_s_phys_addr.part.0+0x68/0x230 [cec]
__cec_s_phys_addr+0x40/0x50 [cec]
cec_unregister_adapter+0xb4/0x118 [cec]
adv7511_remove+0x60/0x90 [adv7511]
i2c_device_remove+0x34/0xe0
device_release_driver_internal+0x114/0x1f0
driver_detach+0x54/0xe0
bus_remove_driver+0x60/0xd8
driver_unregister+0x34/0x60
i2c_del_driver+0x2c/0x68
adv7511_exit+0x1c/0x67c [adv7511]
__arm64_sys_delete_module+0x154/0x288
invoke_syscall+0x48/0x100
el0_svc_common.constprop.0+0x48/0xe8
do_el0_svc+0x28/0x88
el0_svc+0x1c/0x50
el0t_64_sync_handler+0xa8/0xb0
el0t_64_sync+0x15c/0x160
Code: bad PC value
---[ end trace 0000000000000000 ]---
Protect against this scenario by unregistering i2c_cec after
unregistering the CEC adapter. Duly disable the CEC clock afterwards
too.
Fixes: 3b1b975003e4 ("drm: adv7511/33: add HDMI CEC support")
Signed-off-by: Alvin Šipraga <alsi@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
index 5bb9300040dd..023c0ad132e0 100644
--- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
+++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
@@ -1339,9 +1339,6 @@ static int adv7511_remove(struct i2c_client *i2c)
{
struct adv7511 *adv7511 = i2c_get_clientdata(i2c);
- i2c_unregister_device(adv7511->i2c_cec);
- clk_disable_unprepare(adv7511->cec_clk);
-
adv7511_uninit_regulators(adv7511);
drm_bridge_remove(&adv7511->bridge);
@@ -1349,6 +1346,8 @@ static int adv7511_remove(struct i2c_client *i2c)
adv7511_audio_exit(adv7511);
cec_unregister_adapter(adv7511->cec_adap);
+ i2c_unregister_device(adv7511->i2c_cec);
+ clk_disable_unprepare(adv7511->cec_clk);
i2c_unregister_device(adv7511->i2c_packet);
i2c_unregister_device(adv7511->i2c_edid);
--
2.36.1
