[PATCH ath-next] wifi: ath10k: shutdown driver when hardware is unreliable

Loic Poulain loic.poulain at oss.qualcomm.com
Fri Jun 13 05:59:58 PDT 2025


Hi Kang,


On Tue, Jun 10, 2025 at 11:55 AM Kang Yang <kang.yang at oss.qualcomm.com> wrote:
>
> In rare cases, ath10k may lose connection with the PCIe bus due to
> some unknown reasons, which could further lead to system crashes during
> resuming due to watchdog timeout:
>
> ath10k_pci 0000:01:00.0: wmi command 20486 timeout, restarting hardware
> ath10k_pci 0000:01:00.0: already restarting
> ath10k_pci 0000:01:00.0: failed to stop WMI vdev 0: -11
> ath10k_pci 0000:01:00.0: failed to stop vdev 0: -11
> ieee80211 phy0: PM: **** DPM device timeout ****
> Call Trace:
>  panic+0x125/0x315
>  dpm_watchdog_set+0x54/0x54
>  dpm_watchdog_handler+0x57/0x57
>  call_timer_fn+0x31/0x13c
>
> At this point, all WMI commands will timeout and attempt to restart
> device. So set a threshold for consecutive restart failures. If the
> threshold is exceeded, consider the hardware is unreliable and all
> ath10k operations should be skipped to avoid system crash.
>
> fail_cont_count and pending_recovery are atomic variables, and
> do not involve complex conditional logic. Therefore, even if recovery
> check and reconfig complete are executed concurrently, the recovery
> mechanism will not be broken.
>
> Tested-on: QCA6174 hw3.2 PCI WLAN.RM.4.4.1-00288-QCARMSWPZ-1
>
> Signed-off-by: Kang Yang <kang.yang at oss.qualcomm.com>
> ---
>  drivers/net/wireless/ath/ath10k/core.c | 50 +++++++++++++++++++++++---
>  drivers/net/wireless/ath/ath10k/core.h | 11 ++++--
>  drivers/net/wireless/ath/ath10k/mac.c  |  7 +++-
>  drivers/net/wireless/ath/ath10k/wmi.c  |  6 ++++
>  4 files changed, 65 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath10k/core.c b/drivers/net/wireless/ath/ath10k/core.c
> index fe3a8f4a1cc1..f925a3cf9ebd 100644
> --- a/drivers/net/wireless/ath/ath10k/core.c
> +++ b/drivers/net/wireless/ath/ath10k/core.c
> @@ -4,6 +4,7 @@
>   * Copyright (c) 2011-2017 Qualcomm Atheros, Inc.
>   * Copyright (c) 2018-2019, The Linux Foundation. All rights reserved.
>   * Copyright (c) 2021-2024 Qualcomm Innovation Center, Inc. All rights reserved.
> + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
>   */
>
>  #include <linux/module.h>
> @@ -2491,12 +2492,51 @@ static int ath10k_init_hw_params(struct ath10k *ar)
>         return 0;
>  }
>
> +static bool ath10k_core_needs_recovery(struct ath10k *ar)
> +{
> +       long time_left;
> +
> +       /* Sometimes the recovery will fail and then the next all recovery fail,
> +        * so avoid infinite recovery.
> +        */
> +       if (atomic_read(&ar->fail_cont_count) >= ATH10K_RECOVERY_MAX_FAIL_COUNT) {
> +               ath10k_err(ar, "consecutive fail %d times, will shutdown driver!",
> +                          atomic_read(&ar->fail_cont_count));
> +               ar->state = ATH10K_STATE_WEDGED;
> +               return false;
> +       }
> +
> +       ath10k_dbg(ar, ATH10K_DBG_BOOT, "total recovery count: %d",

You don't need a newline.

> +                  ++ar->recovery_count);
> +
> +       if (atomic_read(&ar->pending_recovery)) {
> +               /* Sometimes it happened another recovery work before the previous one
> +                * completed, then the second recovery work will destroy the previous
> +                * one, thus below is to avoid that.
> +                */
> +               time_left = wait_for_completion_timeout(&ar->driver_recovery,
> +                                                       ATH10K_RECOVERY_TIMEOUT_HZ);
> +               if (time_left) {
> +                       ath10k_warn(ar, "previous recovery succeeded, skip this!\n");
> +                       return false;
> +               }
> +
> +               /* Record the continuous recovery fail count when recovery failed. */
> +               atomic_inc(&ar->fail_cont_count);
> +
> +               /* Avoid having multiple recoveries at the same time. */
> +               return false;
> +       }
> +
> +       atomic_inc(&ar->pending_recovery);
> +
> +       return true;
> +}
> +
>  void ath10k_core_start_recovery(struct ath10k *ar)
>  {
> -       if (test_and_set_bit(ATH10K_FLAG_RESTARTING, &ar->dev_flags)) {
> -               ath10k_warn(ar, "already restarting\n");
> +       if (!ath10k_core_needs_recovery(ar))
>                 return;
> -       }
>
>         queue_work(ar->workqueue, &ar->restart_work);
>  }
> @@ -2532,6 +2572,8 @@ static void ath10k_core_restart(struct work_struct *work)
>         struct ath10k *ar = container_of(work, struct ath10k, restart_work);
>         int ret;
>
> +       reinit_completion(&ar->driver_recovery);
> +
>         set_bit(ATH10K_FLAG_CRASH_FLUSH, &ar->dev_flags);
>
>         /* Place a barrier to make sure the compiler doesn't reorder
> @@ -2596,8 +2638,6 @@ static void ath10k_core_restart(struct work_struct *work)
>         if (ret)
>                 ath10k_warn(ar, "failed to send firmware crash dump via devcoredump: %d",
>                             ret);
> -
> -       complete(&ar->driver_recovery);
>  }
>
>  static void ath10k_core_set_coverage_class_work(struct work_struct *work)
> diff --git a/drivers/net/wireless/ath/ath10k/core.h b/drivers/net/wireless/ath/ath10k/core.h
> index 446dca74f06a..06ac95707531 100644
> --- a/drivers/net/wireless/ath/ath10k/core.h
> +++ b/drivers/net/wireless/ath/ath10k/core.h
> @@ -4,6 +4,7 @@
>   * Copyright (c) 2011-2017 Qualcomm Atheros, Inc.
>   * Copyright (c) 2018-2019, The Linux Foundation. All rights reserved.
>   * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
> + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
>   */
>
>  #ifndef _CORE_H_
> @@ -87,6 +88,8 @@
>                                   IEEE80211_IFACE_SKIP_SDATA_NOT_IN_DRIVER)
>  #define ATH10K_ITER_RESUME_FLAGS (IEEE80211_IFACE_ITER_RESUME_ALL |\
>                                   IEEE80211_IFACE_SKIP_SDATA_NOT_IN_DRIVER)
> +#define ATH10K_RECOVERY_TIMEOUT_HZ                     (5 * HZ)
> +#define ATH10K_RECOVERY_MAX_FAIL_COUNT                 4
>
>  struct ath10k;
>
> @@ -865,9 +868,6 @@ enum ath10k_dev_flags {
>         /* Per Station statistics service */
>         ATH10K_FLAG_PEER_STATS,
>
> -       /* Indicates that ath10k device is during recovery process and not complete */
> -       ATH10K_FLAG_RESTARTING,
> -
>         /* protected by conf_mutex */
>         ATH10K_FLAG_NAPI_ENABLED,
>  };
> @@ -1211,6 +1211,11 @@ struct ath10k {
>         struct work_struct bundle_tx_work;
>         struct work_struct tx_complete_work;
>
> +       atomic_t pending_recovery;
> +       u8 recovery_count;

No reason to be a u8 IMO, use unsigned int.

> +       /* continuous recovery fail count */
> +       atomic_t fail_cont_count;
> +



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