4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Mohammed Shafi Shajakhan <[email protected]> commit c2cac2f74ab4bcf0db0dcf3a612f1e5b52d145c8 upstream. 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' Fixes: 3c97f5de1f28 ("ath10k: implement NAPI support") Signed-off-by: Mohammed Shafi Shajakhan <[email protected]> Signed-off-by: Kalle Valo <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/net/wireless/ath/ath10k/core.c | 2 +- drivers/net/wireless/ath/ath10k/mac.c | 1 - 2 files changed, 1 insertion(+), 2 deletions(-) --- a/drivers/net/wireless/ath/ath10k/core.c +++ b/drivers/net/wireless/ath/ath10k/core.c @@ -1534,7 +1534,7 @@ static void ath10k_core_restart(struct w 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; --- 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 ar->state = ATH10K_STATE_ON; break; case ATH10K_STATE_RESTARTING: - ath10k_halt(ar); ar->state = ATH10K_STATE_RESTARTED; break; case ATH10K_STATE_ON:
