Commit Message
Greg KH
Oct. 24, 2022, 11:29 a.m. UTC
From: Alvin Šipraga <alsi@bang-olufsen.dk> [ Upstream commit 40cdb02cb9f965732eb543d47f15bef8d10f0f5f ] 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@bang-olufsen.dk> Reviewed-by: Robert Foss <robert.foss@linaro.org> Signed-off-by: Robert Foss <robert.foss@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20220612144854.2223873-3-alvin@pqrs.dk Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c index 7e3f6633f255..3dc551d223d6 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c @@ -1326,8 +1326,6 @@ static int adv7511_remove(struct i2c_client *i2c) if (adv7511->type == ADV7533 || adv7511->type == ADV7535) adv7533_detach_dsi(adv7511); - i2c_unregister_device(adv7511->i2c_cec); - clk_disable_unprepare(adv7511->cec_clk); adv7511_uninit_regulators(adv7511); @@ -1336,6 +1334,8 @@ 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);