Hi All, While testing the AMSDU patch and trying to send a AMSDU with each MSDU 2000 bytes and 3 MSDU's in AMSDU observed that the DMA engine times out and causes the below warning. This might be due to a large frame being trasnferred. Tried to check the maximum supported frame by ath9k, but couldnt get. In the Rx side the max skb size is as below (2K=2304). common->rx_bufsize = IEEE80211_MAX_MPDU_LEN / 2 + sc->sc_ah->caps.rx_status_len; What is the maximum skb size we can transmit with ath9k PCIe? Regards, Chaitanya TK. Log: Feb 5 17:28:39 chaitanya-desktop kernel: [12465.510576] ieee80211_if_parse_send_amsdu: 525 Allocaked SKB size of 8192 Bytes: tailRoom: 16128 bytes and 0 HeadRoom Feb 5 17:28:39 chaitanya-desktop kernel: [12465.510578] ieee80211_if_parse_send_amsdu: 531 Creating the Header and Filling it: VIF Type: 2 Feb 5 17:28:39 chaitanya-desktop kernel: [12465.510581] ieee80211_if_parse_send_amsdu: 561 Creating the AMSDU Header and Filling it Feb 5 17:28:39 chaitanya-desktop kernel: [12465.510583] ieee80211_if_parse_send_amsdu: 574 Creating the MSDU : 0 Header: TailRoom: 16102 Feb 5 17:28:39 chaitanya-desktop kernel: [12465.510587] ieee80211_if_parse_send_amsdu: 604 Appening the MSDU to the AMSDU=> Main SKB Feb 5 17:28:39 chaitanya-desktop kernel: [12465.510591] ieee80211_if_parse_send_amsdu: 574 Creating the MSDU : 1 Header: TailRoom: 14078 Feb 5 17:28:39 chaitanya-desktop kernel: [12465.510594] ieee80211_if_parse_send_amsdu: 604 Appening the MSDU to the AMSDU=> Main SKB Feb 5 17:28:39 chaitanya-desktop kernel: [12465.510598] ieee80211_if_parse_send_amsdu: 574 Creating the MSDU : 2 Header: TailRoom: 12054 Feb 5 17:28:39 chaitanya-desktop kernel: [12465.510601] ieee80211_if_parse_send_amsdu: 604 Appening the MSDU to the AMSDU=> Main SKB Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716184] ath: phy0: DMA failed to stop in 10 ms AR_CR=0x00000024 AR_DIAG_SW=0x42000020 DMADBG_7=0x000062c0 Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716190] ath: phy0: Could not stop RX, we could be confusing the DMA engine when we start RX up Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716192] ------------[ cut here ]------------ Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716202] WARNING: at drivers/net/wireless/ath/ath9k/recv.c:497 ath_stoprecv+0xfa/0x110 [ath9k]() Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716204] Hardware name: Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716206] Modules linked in: ath9k(O) mac80211(O) ath9k_common(O) ath9k_hw(O) ath(O) cfg80211(O) arc4 i915 drm_kms_helper coretemp drm snd_hda_codec_realtek snd_hda_intel snd_hda_codec hid_generic usbhid kvm snd_hwdep snd_pcm lpc_ich snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq snd_timer snd_seq_device snd hid soundcore snd_page_alloc i2c_algo_bit video serio_raw microcode binfmt_misc r8169 [last unloaded: cfg80211] Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716249] Pid: 7973, comm: kworker/u:2 Tainted: G O 3.8.0-rc1+ #5 Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716252] Call Trace: Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716261] [<c1038b92>] warn_slowpath_common+0x72/0xa0 Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716269] [<f846c9aa>] ? ath_stoprecv+0xfa/0x110 [ath9k] Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716276] [<f846c9aa>] ? ath_stoprecv+0xfa/0x110 [ath9k] Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716281] [<c1038be2>] warn_slowpath_null+0x22/0x30 Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716288] [<f846c9aa>] ath_stoprecv+0xfa/0x110 [ath9k] Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716295] [<f8468bfa>] ath_prepare_reset+0x5a/0xd0 [ath9k] Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716301] [<f84692ca>] ath_reset_internal+0x6a/0x1a0 [ath9k] Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716307] [<c102d298>] ? default_spin_lock_flags+0x8/0x10 Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716314] [<c159473d>] ? _raw_spin_lock_irqsave+0x2d/0x40 Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716320] [<f84698a5>] ath_reset+0x25/0xb0 [ath9k] Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716327] [<f846b957>] ath_reset_work+0x17/0x20 [ath9k] Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716333] [<c1053c60>] process_one_work+0x110/0x380 Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716337] [<c1594d00>] ? apic_timer_interrupt+0x34/0x3c Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716344] [<f846b940>] ? ath9k_tasklet+0x160/0x160 [ath9k] Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716348] [<c1054699>] worker_thread+0x119/0x350 Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716352] [<c1054580>] ? manage_workers+0x260/0x260 Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716356] [<c1058e34>] kthread+0x94/0xa0 Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716362] [<c1060000>] ? prepare_exec_creds+0x40/0x40 Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716367] [<c159b737>] ret_from_kernel_thread+0x1b/0x28 Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716371] [<c1058da0>] ? flush_kthread_worker+0x90/0x90 Feb 5 17:28:40 chaitanya-desktop kernel: [12466.716374] ---[ end trace f9ddbedd51424709 ]--- Feb 5 17:28:40 chaitanya-desktop kernel: [12466.723551] ath: phy0: Failed to stop TX DMA, queues=0x001! Feb 5 17:28:41 chaitanya-desktop kernel: [12467.504819] ath: phy0: DMA failed to stop in 10 ms AR_CR=0x00000024 AR_DIAG_SW=0x42000020 DMADBG_7=0x00026040 Feb 5 17:28:41 chaitanya-desktop kernel: [12467.504825] ath: phy0: Could not stop RX, we could be confusing the DMA engine when we start RX up Feb 5 17:28:41 chaitanya-desktop kernel: [12467.511965] ath: phy0: Failed to stop TX DMA, queues=0x001! Feb 5 17:28:41 chaitanya-desktop kernel: [12467.514097] cfg80211: All devices are disconnected, going to restore regulatory settings Feb 5 17:28:41 chaitanya-desktop kernel: [12467.514100] cfg80211: Restoring regulatory settings Feb 5 17:28:41 chaitanya-desktop kernel: [12467.514102] cfg80211: Kicking the queue Feb 5 17:28:41 chaitanya-desktop kernel: [12467.514106] cfg80211: Calling CRDA to update world regulatory domain Feb 5 17:28:41 chaitanya-desktop kernel: [12467.517416] cfg80211: Updating information on frequency 2412 MHz with regulatory rule: Feb 5 17:28:41 chaitanya-desktop kernel: [12467.517419] cfg80211: 2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2700 mBm) Feb 5 17:28:41 chaitanya-desktop kernel: [12467.517420] cfg80211: Updating information on frequency 2417 MHz with regulatory rule: -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html