From: Tsuchiya Yuto kitakar@gmail.com
[ Upstream commit 4add4d988f95f47493500a7a19c623827061589b ]
If a reset is performed, but even the reset fails for some reasons (e.g., on Surface devices, the fw reset requires another quirks), cancel_work_sync() hangs in mwifiex_cleanup_pcie().
# firmware went into a bad state [...] [ 1608.281690] mwifiex_pcie 0000:03:00.0: info: shutdown mwifiex... [ 1608.282724] mwifiex_pcie 0000:03:00.0: rx_pending=0, tx_pending=1, cmd_pending=0 [ 1608.292400] mwifiex_pcie 0000:03:00.0: PREP_CMD: card is removed [ 1608.292405] mwifiex_pcie 0000:03:00.0: PREP_CMD: card is removed # reset performed after firmware went into a bad state [ 1609.394320] mwifiex_pcie 0000:03:00.0: WLAN FW already running! Skip FW dnld [ 1609.394335] mwifiex_pcie 0000:03:00.0: WLAN FW is active # but even the reset failed [ 1619.499049] mwifiex_pcie 0000:03:00.0: mwifiex_cmd_timeout_func: Timeout cmd id = 0xfa, act = 0xe000 [ 1619.499094] mwifiex_pcie 0000:03:00.0: num_data_h2c_failure = 0 [ 1619.499103] mwifiex_pcie 0000:03:00.0: num_cmd_h2c_failure = 0 [ 1619.499110] mwifiex_pcie 0000:03:00.0: is_cmd_timedout = 1 [ 1619.499117] mwifiex_pcie 0000:03:00.0: num_tx_timeout = 0 [ 1619.499124] mwifiex_pcie 0000:03:00.0: last_cmd_index = 0 [ 1619.499133] mwifiex_pcie 0000:03:00.0: last_cmd_id: fa 00 07 01 07 01 07 01 07 01 [ 1619.499140] mwifiex_pcie 0000:03:00.0: last_cmd_act: 00 e0 00 00 00 00 00 00 00 00 [ 1619.499147] mwifiex_pcie 0000:03:00.0: last_cmd_resp_index = 3 [ 1619.499155] mwifiex_pcie 0000:03:00.0: last_cmd_resp_id: 07 81 07 81 07 81 07 81 07 81 [ 1619.499162] mwifiex_pcie 0000:03:00.0: last_event_index = 2 [ 1619.499169] mwifiex_pcie 0000:03:00.0: last_event: 58 00 58 00 58 00 58 00 58 00 [ 1619.499177] mwifiex_pcie 0000:03:00.0: data_sent=0 cmd_sent=1 [ 1619.499185] mwifiex_pcie 0000:03:00.0: ps_mode=0 ps_state=0 [ 1619.499215] mwifiex_pcie 0000:03:00.0: info: _mwifiex_fw_dpc: unregister device # mwifiex_pcie_work hang happening [ 1823.233923] INFO: task kworker/3:1:44 blocked for more than 122 seconds. [ 1823.233932] Tainted: G WC OE 5.10.0-rc1-1-mainline #1 [ 1823.233935] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1823.233940] task:kworker/3:1 state:D stack: 0 pid: 44 ppid: 2 flags:0x00004000 [ 1823.233960] Workqueue: events mwifiex_pcie_work [mwifiex_pcie] [ 1823.233965] Call Trace: [ 1823.233981] __schedule+0x292/0x820 [ 1823.233990] schedule+0x45/0xe0 [ 1823.233995] schedule_timeout+0x11c/0x160 [ 1823.234003] wait_for_completion+0x9e/0x100 [ 1823.234012] __flush_work.isra.0+0x156/0x210 [ 1823.234018] ? flush_workqueue_prep_pwqs+0x130/0x130 [ 1823.234026] __cancel_work_timer+0x11e/0x1a0 [ 1823.234035] mwifiex_cleanup_pcie+0x28/0xd0 [mwifiex_pcie] [ 1823.234049] mwifiex_free_adapter+0x24/0xe0 [mwifiex] [ 1823.234060] _mwifiex_fw_dpc+0x294/0x560 [mwifiex] [ 1823.234074] mwifiex_reinit_sw+0x15d/0x300 [mwifiex] [ 1823.234080] mwifiex_pcie_reset_done+0x50/0x80 [mwifiex_pcie] [ 1823.234087] pci_try_reset_function+0x5c/0x90 [ 1823.234094] process_one_work+0x1d6/0x3a0 [ 1823.234100] worker_thread+0x4d/0x3d0 [ 1823.234107] ? rescuer_thread+0x410/0x410 [ 1823.234112] kthread+0x142/0x160 [ 1823.234117] ? __kthread_bind_mask+0x60/0x60 [ 1823.234124] ret_from_fork+0x22/0x30 [...]
This is a deadlock caused by calling cancel_work_sync() in mwifiex_cleanup_pcie():
- Device resets are done via mwifiex_pcie_card_reset() - which schedules card->work to call mwifiex_pcie_card_reset_work() - which calls pci_try_reset_function(). - This leads to mwifiex_pcie_reset_done() be called on the same workqueue, which in turn calls - mwifiex_reinit_sw() and that calls - _mwifiex_fw_dpc().
The problem is now that _mwifiex_fw_dpc() calls mwifiex_free_adapter() in case firmware initialization fails. That ends up calling mwifiex_cleanup_pcie().
Note that all those calls are still running on the workqueue. So when mwifiex_cleanup_pcie() now calls cancel_work_sync(), it's really waiting on itself to complete, causing a deadlock.
This commit fixes the deadlock by skipping cancel_work_sync() on a reset failure path.
After this commit, when reset fails, the following output is expected to be shown:
kernel: mwifiex_pcie 0000:03:00.0: info: _mwifiex_fw_dpc: unregister device kernel: mwifiex: Failed to bring up adapter: -5 kernel: mwifiex_pcie 0000:03:00.0: reinit failed: -5
To reproduce this issue, for example, try putting the root port of wifi into D3 (replace "00:1d.3" with your setup).
# put into D3 (root port) sudo setpci -v -s 00:1d.3 CAP_PM+4.b=0b
Cc: Maximilian Luz luzmaximilian@gmail.com Signed-off-by: Tsuchiya Yuto kitakar@gmail.com Signed-off-by: Kalle Valo kvalo@codeaurora.org Link: https://lore.kernel.org/r/20201028142346.18355-1-kitakar@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wireless/marvell/mwifiex/pcie.c | 18 +++++++++++++++++- drivers/net/wireless/marvell/mwifiex/pcie.h | 2 ++ 2 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/drivers/net/wireless/marvell/mwifiex/pcie.c b/drivers/net/wireless/marvell/mwifiex/pcie.c index 6a10ff0377a24..33cf952cc01d3 100644 --- a/drivers/net/wireless/marvell/mwifiex/pcie.c +++ b/drivers/net/wireless/marvell/mwifiex/pcie.c @@ -526,6 +526,8 @@ static void mwifiex_pcie_reset_prepare(struct pci_dev *pdev) clear_bit(MWIFIEX_IFACE_WORK_DEVICE_DUMP, &card->work_flags); clear_bit(MWIFIEX_IFACE_WORK_CARD_RESET, &card->work_flags); mwifiex_dbg(adapter, INFO, "%s, successful\n", __func__); + + card->pci_reset_ongoing = true; }
/* @@ -554,6 +556,8 @@ static void mwifiex_pcie_reset_done(struct pci_dev *pdev) dev_err(&pdev->dev, "reinit failed: %d\n", ret); else mwifiex_dbg(adapter, INFO, "%s, successful\n", __func__); + + card->pci_reset_ongoing = false; }
static const struct pci_error_handlers mwifiex_pcie_err_handler = { @@ -3142,7 +3146,19 @@ static void mwifiex_cleanup_pcie(struct mwifiex_adapter *adapter) int ret; u32 fw_status;
- cancel_work_sync(&card->work); + /* Perform the cancel_work_sync() only when we're not resetting + * the card. It's because that function never returns if we're + * in reset path. If we're here when resetting the card, it means + * that we failed to reset the card (reset failure path). + */ + if (!card->pci_reset_ongoing) { + mwifiex_dbg(adapter, MSG, "performing cancel_work_sync()...\n"); + cancel_work_sync(&card->work); + mwifiex_dbg(adapter, MSG, "cancel_work_sync() done\n"); + } else { + mwifiex_dbg(adapter, MSG, + "skipped cancel_work_sync() because we're in card reset failure path\n"); + }
ret = mwifiex_read_reg(adapter, reg->fw_status, &fw_status); if (fw_status == FIRMWARE_READY_PCIE) { diff --git a/drivers/net/wireless/marvell/mwifiex/pcie.h b/drivers/net/wireless/marvell/mwifiex/pcie.h index 843d57eda8201..5ed613d657094 100644 --- a/drivers/net/wireless/marvell/mwifiex/pcie.h +++ b/drivers/net/wireless/marvell/mwifiex/pcie.h @@ -242,6 +242,8 @@ struct pcie_service_card { struct mwifiex_msix_context share_irq_ctx; struct work_struct work; unsigned long work_flags; + + bool pci_reset_ongoing; };
static inline int