We setup the HNP polling worker, but we never stop it. The OTG state machine can go round and round and keep reinitializing the worker even while it's actively running. That's bad, and debug objects catches it. Fix this by canceling the work when we leave the A_HOST or B_HOST states. [otg_set_state] Set state: a_wait_bcon usb 2-1: USB disconnect, device number 2 [otg_statemachine] quit statemachine, changed = 1 [otg_set_state] Set state: a_host <HNP Polling started> [otg_statemachine] quit statemachine, changed = 1 usb 2-1: new low-speed USB device number 3 using ci_hdrc usb 2-1: New USB device found, idVendor=03f0, idProduct=134a usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0 usb 2-1: Product: HP USB Optical Mouse usb 2-1: Manufacturer: PixArt input: PixArt HP USB Optical Mouse as /devices/platform/soc/f9a55000.usb/ci_hdrc.0/usb2/2-1/2-1:1.0/0003:03F0:134A.0002/input/input1 hid-generic 0003:03F0:134A.0002: input: USB HID v1.11 Mouse [PixArt HP USB Optical Mouse] on usb-ci_hdrc.0-1/input0 [otg_set_state] Set state: a_wait_bcon usb 2-1: USB disconnect, device number 3 [otg_statemachine] quit statemachine, changed = 1 [otg_set_state] Set state: a_host <HNP Polling started> ------------[ cut here ]------------ WARNING: CPU: 2 PID: 95 at lib/debugobjects.c:263 debug_print_object+0x98/0xc0 ODEBUG: init active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x2c Modules linked in: phy_qcom_usb_hsic phy_qcom_usb_hs ci_hdrc_msm ci_hdrc CPU: 2 PID: 95 Comm: kworker/u8:1 Not tainted 4.7.0-rc1-00043-g1f22f3b65c44-dirty #442 Hardware name: Qualcomm (Flattened Device Tree) Workqueue: ci_otg ci_otg_work [ci_hdrc] [<c031067c>] (unwind_backtrace) from [<c030cbf0>] (show_stack+0x20/0x24) [<c030cbf0>] (show_stack) from [<c060cec8>] (dump_stack+0x7c/0x9c) [<c060cec8>] (dump_stack) from [<c031f8a4>] (__warn+0xe4/0x110) [<c031f8a4>] (__warn) from [<c031f9a0>] (warn_slowpath_fmt+0x48/0x50) [<c031f9a0>] (warn_slowpath_fmt) from [<c06289c0>] (debug_print_object+0x98/0xc0) [<c06289c0>] (debug_print_object) from [<c0628bbc>] (__debug_object_init+0xcc/0x3bc) [<c0628bbc>] (__debug_object_init) from [<c0628ed0>] (debug_object_init+0x24/0x2c) [<c0628ed0>] (debug_object_init) from [<c037ceb0>] (init_timer_key+0x24/0x120) [<c037ceb0>] (init_timer_key) from [<c07b3f1c>] (otg_start_hnp_polling+0x7c/0xbc) [<c07b3f1c>] (otg_start_hnp_polling) from [<c074543c>] (otg_set_state+0x740/0xc20) [<c074543c>] (otg_set_state) from [<c0745d98>] (otg_statemachine+0x47c/0x4ac) [<c0745d98>] (otg_statemachine) from [<bf00c808>] (ci_otg_fsm_work+0x48/0x1a0 [ci_hdrc]) [<bf00c808>] (ci_otg_fsm_work [ci_hdrc]) from [<bf007428>] (ci_otg_work+0xd4/0x218 [ci_hdrc]) [<bf007428>] (ci_otg_work [ci_hdrc]) from [<c0338cac>] (process_one_work+0x154/0x4b4) [<c0338cac>] (process_one_work) from [<c033908c>] (worker_thread+0x38/0x4d0) [<c033908c>] (worker_thread) from [<c033f0a0>] (kthread+0xe8/0x104) [<c033f0a0>] (kthread) from [<c0308ed8>] (ret_from_fork+0x14/0x3c) Cc: Li Jun <jun.li@xxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Fixes: ae57e97a9521 ("usb: common: otg-fsm: add HNP polling support") Signed-off-by: Stephen Boyd <stephen.boyd@xxxxxxxxxx> --- drivers/usb/common/usb-otg-fsm.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/usb/common/usb-otg-fsm.c b/drivers/usb/common/usb-otg-fsm.c index 9059b7dc185e..73eec8c12235 100644 --- a/drivers/usb/common/usb-otg-fsm.c +++ b/drivers/usb/common/usb-otg-fsm.c @@ -61,6 +61,18 @@ static int otg_set_protocol(struct otg_fsm *fsm, int protocol) return 0; } +static void otg_stop_hnp_polling(struct otg_fsm *fsm) +{ + /* + * The memory of host_req_flag should be allocated by + * controller driver, otherwise, hnp polling is not started. + */ + if (!fsm->host_req_flag) + return; + + cancel_delayed_work_sync(&fsm->hnp_polling_work); +} + /* Called when leaving a state. Do state clean up jobs here */ static void otg_leave_state(struct otg_fsm *fsm, enum usb_otg_state old_state) { @@ -84,6 +96,7 @@ static void otg_leave_state(struct otg_fsm *fsm, enum usb_otg_state old_state) fsm->b_ase0_brst_tmout = 0; break; case OTG_STATE_B_HOST: + otg_stop_hnp_polling(fsm); break; case OTG_STATE_A_IDLE: fsm->adp_prb = 0; @@ -97,6 +110,7 @@ static void otg_leave_state(struct otg_fsm *fsm, enum usb_otg_state old_state) fsm->a_wait_bcon_tmout = 0; break; case OTG_STATE_A_HOST: + otg_stop_hnp_polling(fsm); otg_del_timer(fsm, A_WAIT_ENUM); break; case OTG_STATE_A_SUSPEND: -- 2.9.0.rc2.8.ga28705d -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html