Aaradhana Sahu <quic_aarasahu@xxxxxxxxxxx> wrote: > Whenever firmware is crashed in split-phy below WARN_ON() triggered: > > WARNING: CPU: 3 PID: 82 at net/mac80211/driver-ops.c:41 drv_stop+0xac/0xbc > Modules linked in: ath12k qmi_helpers > CPU: 3 PID: 82 Comm: kworker/3:2 Tainted: G D W 6.9.0-next-20240520-00113-gd981a3784e15 #39 > Hardware name: Qualcomm Technologies, Inc. IPQ9574/AP-AL02-C9 (DT) > Workqueue: events_freezable ieee80211_restart_work > pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > pc : drv_stop+0xac/0xbc > lr : ieee80211_stop_device+0x54/0x64 > sp : ffff8000848dbb20 > x29: ffff8000848dbb20 x28: 0000000000000790 x27: ffff000014d78900 > x26: ffff000014d791f8 x25: ffff000007f0d9b0 x24: 0000000000000018 > x23: 0000000000000001 x22: 0000000000000000 x21: ffff000014d78e10 > x20: ffff800081dc0000 x19: ffff000014d78900 x18: ffffffffffffffff > x17: ffff7fffbca84000 x16: ffff800083fe0000 x15: ffff800081dc0b48 > x14: 0000000000000076 x13: 0000000000000076 x12: 0000000000000001 > x11: 0000000000000000 x10: 0000000000000a60 x9 : ffff8000848db980 > x8 : ffff000000dddfc0 x7 : 0000000000000400 x6 : ffff800083b012d8 > x5 : ffff800083b012d8 x4 : 0000000000000000 x3 : ffff000014d78398 > x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff000014d78900 > Call trace: > drv_stop+0xac/0xbc > ieee80211_stop_device+0x54/0x64 > ieee80211_do_stop+0x5a0/0x790 > ieee80211_stop+0x4c/0x178 > __dev_close_many+0xb0/0x150 > dev_close_many+0x88/0x130 > dev_close.part.171+0x44/0x74 > dev_close+0x1c/0x28 > cfg80211_shutdown_all_interfaces+0x44/0xfc > ieee80211_restart_work+0xfc/0x14c > process_scheduled_works+0x18c/0x2dc > worker_thread+0x13c/0x314 > kthread+0x118/0x124 > ret_from_fork+0x10/0x20 > ---[ end trace 0000000000000000 ]--- > > The warning in question is from drv_stop(): > > if (WARN_ON(!local->started)) > return; > > The sequence of WARN_ON() is: > Thread 1: > -Firmware crash calls ath12k_core_reset(). > -Call ieee80211_restart_hw() inside > ath12k_core_post_reconfigure_recovery() which schedules worker > for both hardware. > -Wait for completion of ab->recovery_start. > > Thread 2 (worker thread): > -One hardware acquires rtnl_lock() inside ieee80211_restart_hw() and > calls ath12k_mac_wait_reconfigure() into ath12k_mac_op_start(). > -Hardware is waiting for ab->reconfigure_complete but at this time > recovery_start_count value is 1 because another worker thread > (local->restart_work) is still waiting for rtnl_lock(). > recovery_start_count is not equal to number of radios > (2 in split-phy). So ab->recovery_start complete does not set > due to this, thread 1 is still waiting and not able to perform > hif power down up and firmware reload. > -Wait timeout happens for ab->reconfigure_complete and comeback > to caller (ath12k_mac_op_start()) and sends WMI command to > crashed firmware and gets error. > -This returns error to drv_start() and local->started is set to false. > -Hardware calls cfg80211_shutdown_all_interfaces() after receiving error > inside ieee80211_restart_work() and goes to drv_stop(), here we trigger > WARN_ON as local->started is false. > > To fix this issue call ieee80211_restart_hw() after firmware has been > reloaded. Now, each hardware can send WMI command to firmware > successfully. With this fix we don't need to wait for > ab->recovery_start completion so remove > ath12k_mac_wait_reconfigure(). > > Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.0.1-00029-QCAHKSWPL_SILICONZ-1 > Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.1.1-00209-QCAHKSWPL_SILICONZ-1 > Tested-on: WCN7850 HW2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3 > > Signed-off-by: Aaradhana Sahu <quic_aarasahu@xxxxxxxxxxx> > Acked-by: Jeff Johnson <quic_jjohnson@xxxxxxxxxxx> > Signed-off-by: Kalle Valo <quic_kvalo@xxxxxxxxxxx> Patch applied to ath-next branch of ath.git, thanks. 670d4949bc8e wifi: ath12k: Fix WARN_ON during firmware crash in split-phy -- https://patchwork.kernel.org/project/linux-wireless/patch/20240529034405.2863150-1-quic_aarasahu@xxxxxxxxxxx/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
