From: Ben Greear <[email protected]>
The system can get into a state where the xmit queue
is stopped, but there are no packets pending, so
the queue will not be restarted.
Add logic to the xmit watchdog to attempt to restart
the xmit logic if this situation is detected.
Signed-off-by: Ben Greear <[email protected]>
---
NOTE: This is basically the same as a patch I posted
a day or two ago. It doesn't address the concern of the
reviewer who NACK'd it, but my system will not properly
transmit packets without this patch applied. I realize
this is a bit of a hack, but until we find and fix all
of the other bugs, I think this patch or something similar
should be applied.
Still, this patch should not be applied unless given positive
ACK by the ath9k developers.
:100644 100644 93209d6... ca9d0d3... M drivers/net/wireless/ath/ath9k/ath9k.h
:100644 100644 9e009cc... b0cb792... M drivers/net/wireless/ath/ath9k/debug.c
:100644 100644 d9a4144... 1b3a62c... M drivers/net/wireless/ath/ath9k/xmit.c
drivers/net/wireless/ath/ath9k/ath9k.h | 1 +
drivers/net/wireless/ath/ath9k/debug.c | 4 ++-
drivers/net/wireless/ath/ath9k/xmit.c | 57 +++++++++++++++++++++++++++-----
3 files changed, 52 insertions(+), 10 deletions(-)
diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index 93209d6..ca9d0d3 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -630,6 +630,7 @@ struct ath_softc {
struct ath9k_debug debug;
spinlock_t nodes_lock;
struct list_head nodes; /* basically, stations */
+ unsigned int tx_complete_poll_work_seen;
#endif
struct ath_beacon_config cur_beacon_conf;
struct delayed_work tx_complete_work;
diff --git a/drivers/net/wireless/ath/ath9k/debug.c b/drivers/net/wireless/ath/ath9k/debug.c
index 9e009cc..b0cb792 100644
--- a/drivers/net/wireless/ath/ath9k/debug.c
+++ b/drivers/net/wireless/ath/ath9k/debug.c
@@ -629,9 +629,11 @@ static ssize_t read_file_xmit(struct file *file, char __user *user_buf,
if (buf == NULL)
return -ENOMEM;
- len += sprintf(buf, "Num-Tx-Queues: %i tx-queues-setup: 0x%x\n"
+ len += sprintf(buf, "Num-Tx-Queues: %i tx-queues-setup: 0x%x"
+ " poll-work-seen: %u\n"
"%30s %10s%10s%10s\n\n",
ATH9K_NUM_TX_QUEUES, sc->tx.txqsetup,
+ sc->tx_complete_poll_work_seen,
"BE", "BK", "VI", "VO");
PR("MPDUs Queued: ", queued);
diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index d9a4144..1b3a62c 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -1988,19 +1988,30 @@ static void ath_tx_rc_status(struct ath_buf *bf, struct ath_tx_status *ts,
tx_info->status.rates[tx_rateindex].count = ts->ts_longretry + 1;
}
-static void ath_wake_mac80211_queue(struct ath_softc *sc, int qnum)
+/* Has no locking. */
+static void __ath_wake_mac80211_queue(struct ath_softc *sc, struct ath_txq *txq)
{
- struct ath_txq *txq;
-
- txq = sc->tx.txq_map[qnum];
- spin_lock_bh(&txq->axq_lock);
if (txq->stopped && txq->pending_frames < ATH_MAX_QDEPTH) {
- if (ath_mac80211_start_queue(sc, qnum))
+ if (ath_mac80211_start_queue(sc, txq->axq_qnum))
txq->stopped = 0;
}
+}
+
+/* Has internal locking. */
+static void _ath_wake_mac80211_queue(struct ath_softc *sc, struct ath_txq *txq)
+{
+ spin_lock_bh(&txq->axq_lock);
+ __ath_wake_mac80211_queue(sc, txq);
spin_unlock_bh(&txq->axq_lock);
}
+/* Has internal locking. */
+static void ath_wake_mac80211_queue(struct ath_softc *sc, int qnum)
+{
+ _ath_wake_mac80211_queue(sc, sc->tx.txq_map[qnum]);
+}
+
+
static void ath_tx_processq(struct ath_softc *sc, struct ath_txq *txq)
{
struct ath_hw *ah = sc->sc_ah;
@@ -2101,10 +2112,9 @@ static void ath_tx_processq(struct ath_softc *sc, struct ath_txq *txq)
else
ath_tx_complete_buf(sc, bf, txq, &bf_head, &ts, txok, 0);
- if (txq == sc->tx.txq_map[qnum])
- ath_wake_mac80211_queue(sc, qnum);
-
spin_lock_bh(&txq->axq_lock);
+ __ath_wake_mac80211_queue(sc, txq);
+
if (sc->sc_flags & SC_OP_TXAGGR)
ath_txq_schedule(sc, txq);
spin_unlock_bh(&txq->axq_lock);
@@ -2119,6 +2129,9 @@ static void ath_tx_complete_poll_work(struct work_struct *work)
int i;
bool needreset = false;
unsigned long timeout = msecs_to_jiffies(ATH_TX_COMPLETE_POLL_INT);
+#ifdef CONFIG_ATH9K_DEBUGFS
+ sc->tx_complete_poll_work_seen++;
+#endif
for (i = 0; i < ATH9K_NUM_TX_QUEUES; i++)
if (ATH_TXQ_SETUP(sc, i)) {
@@ -2137,6 +2150,32 @@ static void ath_tx_complete_poll_work(struct work_struct *work)
txq->axq_tx_inprogress = true;
txq->start_tx_timer = jiffies;
}
+ } else {
+ /* If the queue has pending buffers, then it
+ * should be doing tx work (and have axq_depth).
+ * Shouldn't get to this state I think..but
+ * we do.
+ */
+ if (!(sc->sc_flags & (SC_OP_OFFCHANNEL)) &&
+ (txq->pending_frames > 0 ||
+ !list_empty(&txq->axq_acq) ||
+ txq->stopped)) {
+ ath_err(ath9k_hw_common(sc->sc_ah),
+ "txq: %p axq_qnum: %i,"
+ " axq_link: %p"
+ " pending frames: %i"
+ " axq_acq empty: %i"
+ " stopped: %i"
+ " axq_depth: 0 Attempting to"
+ " Restarting tx logic.\n",
+ txq, txq->axq_qnum,
+ txq->axq_link,
+ txq->pending_frames,
+ list_empty(&txq->axq_acq),
+ txq->stopped);
+ __ath_wake_mac80211_queue(sc, txq);
+ ath_txq_schedule(sc, txq);
+ }
}
spin_unlock_bh(&txq->axq_lock);
}
--
1.7.2.3
On 01/09/2011 09:02 PM, Felix Fietkau wrote:
> On 2011-01-09 9:39 PM, Ben Greear wrote:
>> On 01/09/2011 10:19 AM, Felix Fietkau wrote:
>>> On 2011-01-09 12:46 AM, [email protected] wrote:
>>>> diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
>>>> index d9a4144..1b3a62c 100644
>>>> --- a/drivers/net/wireless/ath/ath9k/xmit.c
>>>> +++ b/drivers/net/wireless/ath/ath9k/xmit.c
>>>> @@ -1988,19 +1988,30 @@ static void ath_tx_rc_status(struct ath_buf *bf, struct ath_tx_status *ts,
>>>> tx_info->status.rates[tx_rateindex].count = ts->ts_longretry + 1;
>>>> }
>>>>
>>>> -static void ath_wake_mac80211_queue(struct ath_softc *sc, int qnum)
>>>> +/* Has no locking. */
>>>> +static void __ath_wake_mac80211_queue(struct ath_softc *sc, struct ath_txq *txq)
>>>> {
>>>> - struct ath_txq *txq;
>>>> -
>>>> - txq = sc->tx.txq_map[qnum];
>>>> - spin_lock_bh(&txq->axq_lock);
>>>> if (txq->stopped&& txq->pending_frames< ATH_MAX_QDEPTH) {
>>>> - if (ath_mac80211_start_queue(sc, qnum))
>>>> + if (ath_mac80211_start_queue(sc, txq->axq_qnum))
>>>> txq->stopped = 0;
>>>> }
>>>> +}
>>> This part is quite broken, I think you got confused with various types of queue numbers. txq->axq_qnum refers to the atheros hw queue index, whereas the qnum
>>> argument to this function refers to the mac80211 queue index (which is also the correct index for sc->tx.txq_map - not to be confused with the sc->tx.txq
>>> array).
>>
>> Yeah, I am confused on all of this. Looks like I should add a member to the txq struct to
>> record it's mac80211 index and use that instead?
> How about just passing the proper qnum? You can get it from the skb queue mapping anyway.
That seems too indirect to me, though that's probably
just paranoia at this point.
>> In the upstream code, is this correct? It seems to me that it should always
>> be waking 'txq' since it just completed a packet. Why the check
>> against txq_map?
>>
>> if (txq == sc->tx.txq_map[qnum])
>> ath_wake_mac80211_queue(sc, qnum);
> Things like CAB (or maybe UAPSD at some point), where a frame might go out through a queue other than the 4 WMM data queues.
Ok, but that code is very subtle and difficult to understand in
my opinion.
I'll re-post my patch with the qnums a bit more explicit..but if you
still think it should be more like it is upstream, I'll re-do the patch.
Thanks,
Ben
>
> - Felix
--
Ben Greear <[email protected]>
Candela Technologies Inc http://www.candelatech.com
On 01/09/2011 10:19 AM, Felix Fietkau wrote:
> On 2011-01-09 12:46 AM, [email protected] wrote:
>> From: Ben Greear<[email protected]>
>>
>> The system can get into a state where the xmit queue
>> is stopped, but there are no packets pending, so
>> the queue will not be restarted.
>>
>> Add logic to the xmit watchdog to attempt to restart
>> the xmit logic if this situation is detected.
>>
>> Signed-off-by: Ben Greear<[email protected]>
>> ---
>>
>> NOTE: This is basically the same as a patch I posted
>> a day or two ago. It doesn't address the concern of the
>> reviewer who NACK'd it, but my system will not properly
>> transmit packets without this patch applied. I realize
>> this is a bit of a hack, but until we find and fix all
>> of the other bugs, I think this patch or something similar
>> should be applied.
>>
>> Still, this patch should not be applied unless given positive
>> ACK by the ath9k developers.
>>
>> diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
>> index d9a4144..1b3a62c 100644
>> --- a/drivers/net/wireless/ath/ath9k/xmit.c
>> +++ b/drivers/net/wireless/ath/ath9k/xmit.c
>> @@ -1988,19 +1988,30 @@ static void ath_tx_rc_status(struct ath_buf *bf, struct ath_tx_status *ts,
>> tx_info->status.rates[tx_rateindex].count = ts->ts_longretry + 1;
>> }
>>
>> -static void ath_wake_mac80211_queue(struct ath_softc *sc, int qnum)
>> +/* Has no locking. */
>> +static void __ath_wake_mac80211_queue(struct ath_softc *sc, struct ath_txq *txq)
>> {
>> - struct ath_txq *txq;
>> -
>> - txq = sc->tx.txq_map[qnum];
>> - spin_lock_bh(&txq->axq_lock);
>> if (txq->stopped&& txq->pending_frames< ATH_MAX_QDEPTH) {
>> - if (ath_mac80211_start_queue(sc, qnum))
>> + if (ath_mac80211_start_queue(sc, txq->axq_qnum))
>> txq->stopped = 0;
>> }
>> +}
> This part is quite broken, I think you got confused with various types of queue numbers. txq->axq_qnum refers to the atheros hw queue index, whereas the qnum
> argument to this function refers to the mac80211 queue index (which is also the correct index for sc->tx.txq_map - not to be confused with the sc->tx.txq array).
Yeah, I am confused on all of this. Looks like I should add a member to the txq struct to
record it's mac80211 index and use that instead?
In the upstream code, is this correct? It seems to me that it should always
be waking 'txq' since it just completed a packet. Why the check
against txq_map?
if (txq == sc->tx.txq_map[qnum])
ath_wake_mac80211_queue(sc, qnum);
> Pushing the locking out to the caller side (with a wrapper) does sound like a good idea though.
Thanks,
Ben
--
Ben Greear <[email protected]>
Candela Technologies Inc http://www.candelatech.com
On 2011-01-09 12:46 AM, [email protected] wrote:
> From: Ben Greear<[email protected]>
>
> The system can get into a state where the xmit queue
> is stopped, but there are no packets pending, so
> the queue will not be restarted.
>
> Add logic to the xmit watchdog to attempt to restart
> the xmit logic if this situation is detected.
>
> Signed-off-by: Ben Greear<[email protected]>
> ---
>
> NOTE: This is basically the same as a patch I posted
> a day or two ago. It doesn't address the concern of the
> reviewer who NACK'd it, but my system will not properly
> transmit packets without this patch applied. I realize
> this is a bit of a hack, but until we find and fix all
> of the other bugs, I think this patch or something similar
> should be applied.
>
> Still, this patch should not be applied unless given positive
> ACK by the ath9k developers.
>
> diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
> index d9a4144..1b3a62c 100644
> --- a/drivers/net/wireless/ath/ath9k/xmit.c
> +++ b/drivers/net/wireless/ath/ath9k/xmit.c
> @@ -1988,19 +1988,30 @@ static void ath_tx_rc_status(struct ath_buf *bf, struct ath_tx_status *ts,
> tx_info->status.rates[tx_rateindex].count = ts->ts_longretry + 1;
> }
>
> -static void ath_wake_mac80211_queue(struct ath_softc *sc, int qnum)
> +/* Has no locking. */
> +static void __ath_wake_mac80211_queue(struct ath_softc *sc, struct ath_txq *txq)
> {
> - struct ath_txq *txq;
> -
> - txq = sc->tx.txq_map[qnum];
> - spin_lock_bh(&txq->axq_lock);
> if (txq->stopped&& txq->pending_frames< ATH_MAX_QDEPTH) {
> - if (ath_mac80211_start_queue(sc, qnum))
> + if (ath_mac80211_start_queue(sc, txq->axq_qnum))
> txq->stopped = 0;
> }
> +}
This part is quite broken, I think you got confused with various types
of queue numbers. txq->axq_qnum refers to the atheros hw queue index,
whereas the qnum argument to this function refers to the mac80211 queue
index (which is also the correct index for sc->tx.txq_map - not to be
confused with the sc->tx.txq array).
Pushing the locking out to the caller side (with a wrapper) does sound
like a good idea though.
- Felix
On 2011-01-09 9:39 PM, Ben Greear wrote:
> On 01/09/2011 10:19 AM, Felix Fietkau wrote:
>> On 2011-01-09 12:46 AM, [email protected] wrote:
>>> diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
>>> index d9a4144..1b3a62c 100644
>>> --- a/drivers/net/wireless/ath/ath9k/xmit.c
>>> +++ b/drivers/net/wireless/ath/ath9k/xmit.c
>>> @@ -1988,19 +1988,30 @@ static void ath_tx_rc_status(struct ath_buf *bf, struct ath_tx_status *ts,
>>> tx_info->status.rates[tx_rateindex].count = ts->ts_longretry + 1;
>>> }
>>>
>>> -static void ath_wake_mac80211_queue(struct ath_softc *sc, int qnum)
>>> +/* Has no locking. */
>>> +static void __ath_wake_mac80211_queue(struct ath_softc *sc, struct ath_txq *txq)
>>> {
>>> - struct ath_txq *txq;
>>> -
>>> - txq = sc->tx.txq_map[qnum];
>>> - spin_lock_bh(&txq->axq_lock);
>>> if (txq->stopped&& txq->pending_frames< ATH_MAX_QDEPTH) {
>>> - if (ath_mac80211_start_queue(sc, qnum))
>>> + if (ath_mac80211_start_queue(sc, txq->axq_qnum))
>>> txq->stopped = 0;
>>> }
>>> +}
>> This part is quite broken, I think you got confused with various types of queue numbers. txq->axq_qnum refers to the atheros hw queue index, whereas the qnum
>> argument to this function refers to the mac80211 queue index (which is also the correct index for sc->tx.txq_map - not to be confused with the sc->tx.txq array).
>
> Yeah, I am confused on all of this. Looks like I should add a member to the txq struct to
> record it's mac80211 index and use that instead?
How about just passing the proper qnum? You can get it from the skb
queue mapping anyway.
> In the upstream code, is this correct? It seems to me that it should always
> be waking 'txq' since it just completed a packet. Why the check
> against txq_map?
>
> if (txq == sc->tx.txq_map[qnum])
> ath_wake_mac80211_queue(sc, qnum);
Things like CAB (or maybe UAPSD at some point), where a frame might go
out through a queue other than the 4 WMM data queues.
- Felix