Hi Kang,
On Tue, Jun 10, 2025 at 11:55 AM Kang Yang <kang.y...@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.y...@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.
