Peter Seiderer <ps.report@xxxxxxx> writes:
> Hello Toke,
>
> On Fri, 1 Apr 2022 19:26:57 +0200, Peter Seiderer <ps.report@xxxxxxx> wrote:
>
>> Hello Toke,
>>
>> On Wed, 30 Mar 2022 18:44:09 +0200, Toke Høiland-Jørgensen <toke@xxxxxxx> wrote:
>>
>> > The ath9k driver was not properly clearing the status area in the
>> > ieee80211_tx_info struct before reporting TX status to mac80211. Instead,
>> > it was manually filling in fields, which meant that fields introduced later
>> > were left as-is.
>> >
>> > Conveniently, mac80211 actually provides a helper to zero out the status
>> > area, so use that to make sure we zero everything.
>> >
>> > The last commit touching the driver function writing the status information
>> > seems to have actually been fixing an issue that was also caused by the
>> > area being uninitialised; but it only added clearing of a single field
>> > instead of the whole struct. That is now redundant, though, so revert that
>> > commit and use it as a convenient Fixes tag.
>> >
>> > Fixes: cc591d77aba1 ("ath9k: Make sure to zero status.tx_time before reporting TX status")
>> > Reported-by: Bagas Sanjaya <bagasdotme@xxxxxxxxx>
>> > Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxx>
>> > ---
>> > drivers/net/wireless/ath/ath9k/xmit.c | 5 ++---
>> > 1 file changed, 2 insertions(+), 3 deletions(-)
>> >
>> > diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
>> > index d0caf1de2bde..cbcf96ac303e 100644
>> > --- a/drivers/net/wireless/ath/ath9k/xmit.c
>> > +++ b/drivers/net/wireless/ath/ath9k/xmit.c
>> > @@ -2553,6 +2553,8 @@ static void ath_tx_rc_status(struct ath_softc *sc, struct ath_buf *bf,
>> > struct ath_hw *ah = sc->sc_ah;
>> > u8 i, tx_rateindex;
>> >
>> > + ieee80211_tx_info_clear_status(tx_info);
>> > +
>>
>> As this also clears the status.rates[].count, see include/net/mac80211.h:
>>
>> 1195 static inline void
>> 1196 ieee80211_tx_info_clear_status(struct ieee80211_tx_info *info)
>> 1197 {
>> 1198 int i;
>> 1199
>> 1200 BUILD_BUG_ON(offsetof(struct ieee80211_tx_info, status.rates) !=
>> 1201 offsetof(struct ieee80211_tx_info, control.rates));
>> 1202 BUILD_BUG_ON(offsetof(struct ieee80211_tx_info, status.rates) !=
>> 1203 offsetof(struct ieee80211_tx_info, driver_rates));
>> 1204 BUILD_BUG_ON(offsetof(struct ieee80211_tx_info, status.rates) != 8) ;
>> 1205 /* clear the rate counts */
>> 1206 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++)
>> 1207 info->status.rates[i].count = 0;
>> 1208 memset_after(&info->status, 0, rates);
>> 1209 }
>>
>> I would have expected some lines added to restore the count (for the
>> rates with index < tx_rateindex), e.g. as done in
>> drivers/net/wireless/ath/ath5k/base.c:
>>
>> 1731 ieee80211_tx_info_clear_status(info);
>> 1732
>> 1733 for (i = 0; i < ts->ts_final_idx; i++) {
>> 1734 struct ieee80211_tx_rate *r =
>> 1735 &info->status.rates[i];
>> 1736
>> 1737 r->count = tries[i];
>> 1738 }
>>
>> In drivers/net/wireless/ath/ath9k/xmit.c this is only done/changed for
>> the tx_rateindex index (which is often zero in case the first suggested rate
>> succeeds, but in noisy environment is sometimes > 0)...
>>
>> > if (txok)
>> > tx_info->status.ack_signal = ts->ts_rssi;
>> >
>> > @@ -2595,9 +2597,6 @@ static void ath_tx_rc_status(struct ath_softc *sc, struct ath_buf *bf,
>> > }
>> >
>> > tx_info->status.rates[)].count = ts->ts_longretry + 1;
>> > -
>> > - /* we report airtime in ath_tx_count_airtime(), don't report twice */
>> > - tx_info->status.tx_time = 0;
>> > }
>> >
>> > static void ath_tx_processq(struct ath_softc *sc, struct ath_txq *txq)
>>
>>
>> And from drivers/net/wireless/ath/ath9k/xmit.c:
>>
>> 2592 for (i = tx_rateindex + 1; i < hw->max_rates; i++) {
>> 2593 tx_info->status.rates[i].count = 0;
>> 2594 tx_info->status.rates[i].idx = -1;
>> 2595 }
>>
>> Line 2593 can be deleted as status.rates[].count is already zeroed through the
>> ieee80211_tx_info_clear_status() call...
>>
>> And it should be sufficient to do:
>>
>> if (tx_rateindex + 1 < hw->max_rates)
>> tx_info->status.rates[tx_rateindex + 1].idx = -1;
>>
>> Regards,
>> Peter
>
> And one additional problem found with your patch applied (to 5.16.18), the log
> get spammed by:
>
> [ 445.489139] ------------[ cut here ]------------
> [ 445.489150] WARNING: CPU: 0 PID: 8630 at drivers/net/wireless/ath/ath9k/xmit.c:174 ath_tx_complete+0x190/0x1a0 [ath9k]
> [ 445.489178] Modules linked in: ath9k ath9k_common ath9k_hw mac80211 ppp_async ppp_generic slhc xt_u32 xt_TCPMSS xt_tcpmss xt_MASQUERADE iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip6table_filter iptable_filter ip6table_mangle ip6_tables cls_u32 sch_prio qmi_wwan cdc_wdm usbnet qcserial usb_wwan gpio_pca953x xt_tcpudp xt_mark iptable_mangle ip_tables x_tables dummy tqmx86_wdt watchdog i2c_machxo2 gpio_tqmx86 libarc4 ath tqmx86 mfd_core ftdi_sio cfg80211 usbserial nct7802 regmap_i2c [last unloaded: mac80211]
> [ 445.489298] CPU: 0 PID: 8630 Comm: modprobe Tainted: G W 5.16.18+ #2
> [ 445.489307] Hardware name: TQ-Group TQMxE38M X64/Type2 - Board Product Name, BIOS TQMxE38M.5.4.48.0028.12 01/31/2017
> [ 445.489311] EIP: ath_tx_complete+0x190/0x1a0 [ath9k]
> [ 445.489328] Code: ff 75 e8 68 d7 a1 2c f8 89 55 ec e8 d5 4f e3 ff 8b 45 f0 8b 55 ec 83 c4 10 8b 80 58 0a 00 00 e9 a8 fe ff ff 8d b6 00 00 00 00 <0f> 0b c7 42 68 00 00 00 00 e9 1d ff ff ff 66 90 55 89 e5 57 56 89
> [ 445.489336] EAX: 00000000 EBX: c2e67900 ECX: c23cc040 EDX: c235a980
> [ 445.489342] ESI: c235a888 EDI: c2359860 EBP: c1089e18 ESP: c1089dfc
> [ 445.489348] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 EFLAGS: 00010297
> [ 445.489355] CR0: 80050033 CR2: b7f81000 CR3: 02ec7000 CR4: 001006d0
> [ 445.489362] Call Trace:
> [ 445.489366] <SOFTIRQ>
> [ 445.489372] ath_tx_complete_buf+0x100/0x130 [ath9k]
> [ 445.489390] ath_tx_process_buffer+0x187/0xb40 [ath9k]
> [ 445.489407] ? resched_curr+0x1d/0xc0
> [ 445.489419] ? check_preempt_wakeup+0x115/0x250
> [ 445.489429] ? task_fork_fair+0xc0/0x170
> [ 445.489436] ? put_prev_task_fair+0x40/0x40
> [ 445.489444] ? check_preempt_curr+0x62/0x70
> [ 445.489452] ? __local_bh_enable_ip+0x33/0x80
> [ 445.489460] ? _raw_spin_unlock_bh+0x13/0x20
> [ 445.489468] ? ath_txq_unlock_complete+0x5a/0x100 [ath9k]
> [ 445.489485] ? _raw_spin_unlock_irqrestore+0x16/0x30
> [ 445.489492] ? try_to_wake_up+0x7c/0x550
> [ 445.489499] ath_tx_tasklet+0x1de/0x2e0 [ath9k]
> [ 445.489519] ath9k_tasklet+0x22f/0x330 [ath9k]
> [ 445.489535] tasklet_action_common.constprop.0+0x89/0xb0
> [ 445.489544] tasklet_action+0x21/0x30
> [ 445.489551] __do_softirq+0xc5/0x28b
> [ 445.489559] ? __entry_text_end+0x4/0x4
> [ 445.489567] call_on_stack+0x40/0x50
> [ 445.489576] </SOFTIRQ>
> [ 445.489580] ? irq_exit_rcu+0x92/0x100
> [ 445.489587] ? common_interrupt+0x27/0x40
> [ 445.489595] ? asm_common_interrupt+0x102/0x140
> [ 445.489605] ---[ end trace 5c176b666255bca1 ]---
> [ 445.607206] ------------[ cut here ]------------
>
>
> Could be fixed by the following additional change:
>
> --- a/drivers/net/wireless/ath/ath9k/xmit.c
> +++ b/drivers/net/wireless/ath/ath9k/xmit.c
> @@ -2511,9 +2511,12 @@ static void ath_tx_rc_status(struct ath_softc *sc, struct ath_buf *bf,
> struct ieee80211_hw *hw = sc->hw;
> struct ath_hw *ah = sc->sc_ah;
> u8 i, tx_rateindex;
> + bool is_valid_ack_signal = tx_info->status.is_valid_ack_signal;
>
> ieee80211_tx_info_clear_status(tx_info);
>
> + tx_info->status.is_valid_ack_signal = is_valid_ack_signal;
> +
> if (txok)
That doesn't seem right, zeroing is_valid_ack_signal was the whole point
of the first patch... Something seems off in that backtrace; could you
try running it through ./scripts/decode_stacktrace.sh please?
-Toke
