From: Mohammed Shafi Shajakhan <moham...@qti.qualcomm.com> During firmware crash (or) user requested manual restart the system gets into a soft lock up state because of the below root cause.
During user requested hardware restart / firmware crash the system goes into a soft lockup state as 'napi_synchronize' is called after 'napi_disable' (which sets 'NAPI_STATE_SCHED' bit) and it sleeps into infinite loop as it waits for 'NAPI_STATE_SCHED' to be cleared. This condition is hit because 'ath10k_hif_stop' is called twice as below (resulting in calling 'napi_synchronize' after 'napi_disable') 'ath10k_core_restart' -> 'ath10k_hif_stop' (ATH10K_STATE_ON) -> -> 'ieee80211_restart_hw' -> 'ath10k_start' -> 'ath10k_halt' -> 'ath10k_core_stop' -> 'ath10k_hif_stop' (ATH10K_STATE_RESTARTING) Fix this by calling 'ath10k_halt' in ath10k_core_restart itself as it makes more sense before informing mac80211 to restart h/w Also remove 'ath10k_halt' in ath10k_start for the state of 'restarting' Signed-off-by: Mohammed Shafi Shajakhan <moham...@qti.qualcomm.com> --- [thanks to Kalle and Michal for their inputs] drivers/net/wireless/ath/ath10k/core.c | 2 +- drivers/net/wireless/ath/ath10k/mac.c | 1 - 2 files changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/net/wireless/ath/ath10k/core.c b/drivers/net/wireless/ath/ath10k/core.c index 7005e2a..5bc6847 100644 --- a/drivers/net/wireless/ath/ath10k/core.c +++ b/drivers/net/wireless/ath/ath10k/core.c @@ -1536,7 +1536,7 @@ static void ath10k_core_restart(struct work_struct *work) switch (ar->state) { case ATH10K_STATE_ON: ar->state = ATH10K_STATE_RESTARTING; - ath10k_hif_stop(ar); + ath10k_halt(ar); ath10k_scan_finish(ar); ieee80211_restart_hw(ar->hw); break; diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c index 717b2fa..481842b 100644 --- a/drivers/net/wireless/ath/ath10k/mac.c +++ b/drivers/net/wireless/ath/ath10k/mac.c @@ -4449,7 +4449,6 @@ static int ath10k_start(struct ieee80211_hw *hw) ar->state = ATH10K_STATE_ON; break; case ATH10K_STATE_RESTARTING: - ath10k_halt(ar); ar->state = ATH10K_STATE_RESTARTED; break; case ATH10K_STATE_ON: -- 1.9.1