drm/rockchip: cdn-dp: Do not run worker while suspended
authorGuenter Roeck <groeck@chromium.org>
Sun, 5 Feb 2017 07:54:58 +0000 (15:54 +0800)
committerMark Yao <mark.yao@rock-chips.com>
Sun, 5 Feb 2017 08:29:46 +0000 (16:29 +0800)
commit5eb2e6ee97b5e9a8587143db339bc71b28a3e1ca
tree07aad5ee1fc248292ee4513687f9082c0c5995e9
parent83c132ed46a7e9c8ac17be436ef3892850df8695
drm/rockchip: cdn-dp: Do not run worker while suspended

If the driver is in suspended mode, the dp block may be disabled, and
chip registers may not be accessible. Yet, the worker may be triggered
in this situation by an extcon event. If that happens, the following crash
will be seen.

cdn-dp fec00000.dp: [drm:cdn_dp_pd_event_work] *ERROR* Enable dp failed -19
cdn-dp fec00000.dp: [drm:cdn_dp_pd_event_work] Connected, not enabled. Enabling cdn
Bad mode in Error handler detected, code 0xbf000002 -- SError
CPU: 1 PID: 10357 Comm: kworker/1:2 Not tainted 4.4.21-05903-ge0514ea #1
Hardware name: Google Kevin (DT)
Workqueue: events cdn_dp_pd_event_work
task: ffffffc0cda67080 ti: ffffffc0b9b80000 task.ti: ffffffc0b9b80000
PC is at cdn_dp_clock_reset+0x30/0xa8
LR is at cdn_dp_enable+0x1e0/0x69c
...
Call trace:
[<ffffffc0005a7e24>] cdn_dp_pd_event_work+0x58/0x3f4
[<ffffffc0002397f0>] process_one_work+0x240/0x424
[<ffffffc00023a28c>] worker_thread+0x2fc/0x424
[<ffffffc00023f5fc>] kthread+0x10c/0x114
[<ffffffc000203dd0>] ret_from_fork+0x10/0x40

Problem is two-fold: The worker should not run while suspended, and the
suspend function should not call cdn_dp_disable() while the worker is
running.

Signed-off-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Chris Zhong <zyw@rock-chips.com>
drivers/gpu/drm/rockchip/cdn-dp-core.c
drivers/gpu/drm/rockchip/cdn-dp-core.h