On 07/30/2018 01:12 AM, Martin Willi wrote:
Hi, We are experiencing some issues when running ath10k in AP mode. Unfortunately, I didn't manage to reproduce the issue in the lab, but in the field we see it roughly once a day on one out of fifty devices. The symptoms are the logged "SWBA overruns" followed by a kernel WARNING when removing a station (see below), followed by many more "SWBA overruns". It seems that the firmware and kernel get out of sync about the associated stations. The module does not recover, but the whole networking stack gets very sluggish, probably due to a lock held for many seconds. Bringing down the affected network interface takes some extra seconds, but then allows recovering from that issue. We are running 4.14-stable, and tried many firmware versions, including 10.2.4.70-2, 10.2.4-1.0-00040, 10.2.4.70.61-2, 10.2.4.70.67 and firmware-2-ct-full-community-20, but the issue remains. Hardware is QCA9882 on a WLE600VX. I stumbled over a some years old discussion at [1] about tx credit starvation. Is this still the same issue we are seeing? Given that the mentioned newer firmware versions did not help here, is there anything else we can try?
If you use the -ct firmware and the -ct driver, you can configure more than 2 tx-credits. Search for 'TARGET_HTC_MAX_TX_CREDITS_CT' in the -ct driver and change it, maybe to 4 or 6. The support was added in this patch and it has some comments that explain it a bit: https://github.com/greearb/linux-ct-4.16/commit/59acbd0481e8fc2028373ed01a0ec5212990b330 I don't know that it will fix your problem, but it might, and is something to try. The -ct driver also has several other patches that attempt to improve tx credits issues, but I am not sure it resolves everything and a buggy firmware would still cause issues no matter. Thanks, Ben
Thanks! Martin [1] https://lists.infradead.org/pipermail/ath10k/2015-June/005340.html --- 15:27:39 ath10k_pci 0000:01:00.0: SWBA overrun on vdev 0, skipped old beacon 15:27:39 ath10k_pci 0000:01:00.0: SWBA overrun on vdev 0, skipped old beacon 15:27:39 ath10k_pci 0000:01:00.0: SWBA overrun on vdev 0, skipped old beacon 15:27:39 ath10k_pci 0000:01:00.0: SWBA overrun on vdev 0, skipped old beacon 15:27:40 ath10k_pci 0000:01:00.0: SWBA overrun on vdev 0, skipped old beacon 15:27:40 ath10k_pci 0000:01:00.0: SWBA overrun on vdev 0, skipped old beacon 15:27:41 ath10k_pci 0000:01:00.0: SWBA overrun on vdev 0, skipped old beacon 15:27:41 ath10k_pci 0000:01:00.0: SWBA overrun on vdev 0, skipped old beacon 15:27:40 ath10k_pci 0000:01:00.0: SWBA overrun on vdev 0, skipped old beacon 15:27:40 ath10k_pci 0000:01:00.0: SWBA overrun on vdev 0, skipped old beacon 15:27:44 ------------[ cut here ]------------ 15:27:44 WARNING: CPU: 0 PID: 150 at net/mac80211/sta_info.c:976 __sta_info_destroy_part2+0x170/0x174 15:27:44 Modules linked in: xt_comment xt_cluster xt_u32 esp4 xfrm6_mode_tunnel xfrm4_mode_tunnel ebtable_filter ebtables bridge stp llc xt_policy xt_connmark xt_mark xt_set ip_set_hash_ipport ip_set_hash_netnet ip_set iptable_mangle nfnet 15:27:44 CPU: 0 PID: 150 Comm: hostapd Not tainted 4.14.55 #2 15:27:44 Hardware name: Marvell Armada 380/385 (Device Tree) 15:27:44 [<c010fd20>] (unwind_backtrace) from [<c010b9bc>] (show_stack+0x10/0x14) 15:27:44 [<c010b9bc>] (show_stack) from [<c0653fa8>] (dump_stack+0x88/0x9c) 15:27:44 [<c0653fa8>] (dump_stack) from [<c012f110>] (__warn+0xe8/0x100) 15:27:44 [<c012f110>] (__warn) from [<c012f1d8>] (warn_slowpath_null+0x20/0x28) 15:27:44 [<c012f1d8>] (warn_slowpath_null) from [<c060b6e0>] (__sta_info_destroy_part2+0x170/0x174) 15:27:44 [<c060b6e0>] (__sta_info_destroy_part2) from [<c060b704>] (__sta_info_destroy+0x20/0x28) 15:27:44 [<c060b704>] (__sta_info_destroy) from [<c060b77c>] (sta_info_destroy_addr_bss+0x2c/0x44) 15:27:44 [<c060b77c>] (sta_info_destroy_addr_bss) from [<c05ec1f4>] (nl80211_del_station+0xc8/0x100) 15:27:44 [<c05ec1f4>] (nl80211_del_station) from [<c050d050>] (genl_rcv_msg+0x2f8/0x3c8) 15:27:44 [<c050d050>] (genl_rcv_msg) from [<c050c190>] (netlink_rcv_skb+0xac/0x104) 15:27:44 [<c050c190>] (netlink_rcv_skb) from [<c050cd48>] (genl_rcv+0x24/0x34) 15:27:44 [<c050cd48>] (genl_rcv) from [<c050b954>] (netlink_unicast+0x184/0x21c) 15:27:44 [<c050b954>] (netlink_unicast) from [<c050bdec>] (netlink_sendmsg+0x334/0x374) 15:27:44 [<c050bdec>] (netlink_sendmsg) from [<c04bc128>] (sock_sendmsg+0x14/0x24) 15:27:44 [<c04bc128>] (sock_sendmsg) from [<c04bc660>] (___sys_sendmsg+0x214/0x228) 15:27:44 [<c04bc660>] (___sys_sendmsg) from [<c04bd4a0>] (__sys_sendmsg+0x40/0x6c) 15:27:44 [<c04bd4a0>] (__sys_sendmsg) from [<c0107ae0>] (ret_fast_syscall+0x0/0x54) 15:27:44 ---[ end trace 036b835c84274321 ]--- 15:27:44 ath10k_warn: 41 callbacks suppressed 15:27:44 ath10k_pci 0000:01:00.0: SWBA overrun on vdev 0, skipped old beacon 15:27:44 ath10k_pci 0000:01:00.0: SWBA overrun on vdev 0, skipped old beacon 15:27:44 ath10k_pci 0000:01:00.0: SWBA overrun on vdev 0, skipped old beacon 15:27:44 ath10k_pci 0000:01:00.0: SWBA overrun on vdev 0, skipped old beacon 15:27:45 ath10k_pci 0000:01:00.0: SWBA overrun on vdev 0, skipped old beacon
-- Ben Greear <greearb@xxxxxxxxxxxxxxx> Candela Technologies Inc http://www.candelatech.com
