2016-03-08 11:55:42

by Rajkumar Manoharan

[permalink] [raw]
Subject: [PATCH v3] ath10k: move mgmt descriptor limit handle under mgmt_tx

Firmware reserves few descriptors for management frames transmission.
In 16 MBSSID scenario, these slots will be easy exhausted due to frequent
probe responses. So for 10.4 based solutions, probe responses are limited
by a threshold (24).

management tx path is separate for all except tlv based solutions. Since
tlv solutions (qca6174 & qca9377) do not support 16 AP interfaces, it is
safe to move management descriptor limitation check under mgmt_tx
function. Though CPU improvement is negligible, unlikely conditions or
never hit conditions in hot path can be avoided on data transmission.

Signed-off-by: Rajkumar Manoharan <[email protected]>
---
v2:
- rebased on top of Michal changes
v3:
- handle mgmt_inc_pending for htt txmode alone

drivers/net/wireless/ath/ath10k/htt.h | 10 +++----
drivers/net/wireless/ath/ath10k/htt_rx.c | 7 ++++-
drivers/net/wireless/ath/ath10k/htt_tx.c | 45 ++++++++++++++++++++------------
drivers/net/wireless/ath/ath10k/mac.c | 24 +++++++++++------
drivers/net/wireless/ath/ath10k/txrx.c | 18 +++++--------
drivers/net/wireless/ath/ath10k/txrx.h | 4 +--
6 files changed, 65 insertions(+), 43 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/htt.h b/drivers/net/wireless/ath/ath10k/htt.h
index 02cf55d..751f6be 100644
--- a/drivers/net/wireless/ath/ath10k/htt.h
+++ b/drivers/net/wireless/ath/ath10k/htt.h
@@ -1767,11 +1767,11 @@ void ath10k_htt_tx_txq_update(struct ieee80211_hw *hw,
void ath10k_htt_tx_txq_recalc(struct ieee80211_hw *hw,
struct ieee80211_txq *txq);
void ath10k_htt_tx_txq_sync(struct ath10k *ar);
-void ath10k_htt_tx_dec_pending(struct ath10k_htt *htt,
- bool is_mgmt);
-int ath10k_htt_tx_inc_pending(struct ath10k_htt *htt,
- bool is_mgmt,
- bool is_presp);
+void ath10k_htt_tx_dec_pending(struct ath10k_htt *htt);
+int ath10k_htt_tx_inc_pending(struct ath10k_htt *htt);
+void ath10k_htt_tx_mgmt_dec_pending(struct ath10k_htt *htt);
+int ath10k_htt_tx_mgmt_inc_pending(struct ath10k_htt *htt, bool is_mgmt,
+ bool is_presp);

int ath10k_htt_tx_alloc_msdu_id(struct ath10k_htt *htt, struct sk_buff *skb);
void ath10k_htt_tx_free_msdu_id(struct ath10k_htt *htt, u16 msdu_id);
diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
index adf35b0..9892f92 100644
--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -2326,7 +2326,12 @@ void ath10k_htt_t2h_msg_handler(struct ath10k *ar, struct sk_buff *skb)
break;
}

- ath10k_txrx_tx_unref(htt, &tx_done);
+ status = ath10k_txrx_tx_unref(htt, &tx_done);
+ if (!status) {
+ spin_lock_bh(&htt->tx_lock);
+ ath10k_htt_tx_mgmt_dec_pending(htt);
+ spin_unlock_bh(&htt->tx_lock);
+ }
ath10k_mac_tx_push_pending(ar);
break;
}
diff --git a/drivers/net/wireless/ath/ath10k/htt_tx.c b/drivers/net/wireless/ath/ath10k/htt_tx.c
index a30c34e..71eb80c 100644
--- a/drivers/net/wireless/ath/ath10k/htt_tx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_tx.c
@@ -149,46 +149,59 @@ void ath10k_htt_tx_txq_update(struct ieee80211_hw *hw,
spin_unlock_bh(&ar->htt.tx_lock);
}

-void ath10k_htt_tx_dec_pending(struct ath10k_htt *htt,
- bool is_mgmt)
+void ath10k_htt_tx_dec_pending(struct ath10k_htt *htt)
{
lockdep_assert_held(&htt->tx_lock);

- if (is_mgmt)
- htt->num_pending_mgmt_tx--;
-
htt->num_pending_tx--;
if (htt->num_pending_tx == htt->max_num_pending_tx - 1)
ath10k_mac_tx_unlock(htt->ar, ATH10K_TX_PAUSE_Q_FULL);
}

-int ath10k_htt_tx_inc_pending(struct ath10k_htt *htt,
- bool is_mgmt,
- bool is_presp)
+int ath10k_htt_tx_inc_pending(struct ath10k_htt *htt)
+{
+ lockdep_assert_held(&htt->tx_lock);
+
+ if (htt->num_pending_tx >= htt->max_num_pending_tx)
+ return -EBUSY;
+
+ htt->num_pending_tx++;
+ if (htt->num_pending_tx == htt->max_num_pending_tx)
+ ath10k_mac_tx_lock(htt->ar, ATH10K_TX_PAUSE_Q_FULL);
+
+ return 0;
+}
+
+int ath10k_htt_tx_mgmt_inc_pending(struct ath10k_htt *htt, bool is_mgmt,
+ bool is_presp)
{
struct ath10k *ar = htt->ar;

lockdep_assert_held(&htt->tx_lock);

+ if (!is_mgmt)
+ return 0;
+
if (htt->num_pending_tx >= htt->max_num_pending_tx)
return -EBUSY;

- if (is_mgmt &&
- is_presp &&
+ if (is_presp &&
ar->hw_params.max_probe_resp_desc_thres &&
ar->hw_params.max_probe_resp_desc_thres < htt->num_pending_mgmt_tx)
return -EBUSY;

- if (is_mgmt)
- htt->num_pending_mgmt_tx++;
-
- htt->num_pending_tx++;
- if (htt->num_pending_tx == htt->max_num_pending_tx)
- ath10k_mac_tx_lock(htt->ar, ATH10K_TX_PAUSE_Q_FULL);
+ htt->num_pending_mgmt_tx++;

return 0;
}

+void ath10k_htt_tx_mgmt_dec_pending(struct ath10k_htt *htt)
+{
+ lockdep_assert_held(&htt->tx_lock);
+
+ htt->num_pending_mgmt_tx--;
+}
+
int ath10k_htt_tx_alloc_msdu_id(struct ath10k_htt *htt, struct sk_buff *skb)
{
struct ath10k *ar = htt->ar;
diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c
index ebff9c0..9d064c7 100644
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -3699,8 +3699,6 @@ static bool ath10k_mac_tx_can_push(struct ieee80211_hw *hw,
int ath10k_mac_tx_push_txq(struct ieee80211_hw *hw,
struct ieee80211_txq *txq)
{
- const bool is_mgmt = false;
- const bool is_presp = false;
struct ath10k *ar = hw->priv;
struct ath10k_htt *htt = &ar->htt;
struct ath10k_txq *artxq = (void *)txq->drv_priv;
@@ -3713,7 +3711,7 @@ int ath10k_mac_tx_push_txq(struct ieee80211_hw *hw,
int ret;

spin_lock_bh(&ar->htt.tx_lock);
- ret = ath10k_htt_tx_inc_pending(htt, is_mgmt, is_presp);
+ ret = ath10k_htt_tx_inc_pending(htt);
spin_unlock_bh(&ar->htt.tx_lock);

if (ret)
@@ -3722,7 +3720,7 @@ int ath10k_mac_tx_push_txq(struct ieee80211_hw *hw,
skb = ieee80211_tx_dequeue(hw, txq);
if (!skb) {
spin_lock_bh(&ar->htt.tx_lock);
- ath10k_htt_tx_dec_pending(htt, is_mgmt);
+ ath10k_htt_tx_dec_pending(htt);
spin_unlock_bh(&ar->htt.tx_lock);

return -ENOENT;
@@ -3739,7 +3737,7 @@ int ath10k_mac_tx_push_txq(struct ieee80211_hw *hw,
ath10k_warn(ar, "failed to push frame: %d\n", ret);

spin_lock_bh(&ar->htt.tx_lock);
- ath10k_htt_tx_dec_pending(htt, is_mgmt);
+ ath10k_htt_tx_dec_pending(htt);
spin_unlock_bh(&ar->htt.tx_lock);

return ret;
@@ -3981,11 +3979,10 @@ static void ath10k_mac_op_tx(struct ieee80211_hw *hw,

if (is_htt) {
spin_lock_bh(&ar->htt.tx_lock);
-
is_mgmt = ieee80211_is_mgmt(hdr->frame_control);
is_presp = ieee80211_is_probe_resp(hdr->frame_control);

- ret = ath10k_htt_tx_inc_pending(htt, is_mgmt, is_presp);
+ ret = ath10k_htt_tx_inc_pending(htt);
if (ret) {
ath10k_warn(ar, "failed to increase tx pending count: %d, dropping\n",
ret);
@@ -3994,6 +3991,15 @@ static void ath10k_mac_op_tx(struct ieee80211_hw *hw,
return;
}

+ ret = ath10k_htt_tx_mgmt_inc_pending(htt, is_mgmt, is_presp);
+ if (ret) {
+ ath10k_warn(ar, "failed to increase tx mgmt pending count: %d, dropping\n",
+ ret);
+ ath10k_htt_tx_dec_pending(htt);
+ spin_unlock_bh(&ar->htt.tx_lock);
+ ieee80211_free_txskb(ar->hw, skb);
+ return;
+ }
spin_unlock_bh(&ar->htt.tx_lock);
}

@@ -4002,7 +4008,9 @@ static void ath10k_mac_op_tx(struct ieee80211_hw *hw,
ath10k_warn(ar, "failed to transmit frame: %d\n", ret);
if (is_htt) {
spin_lock_bh(&ar->htt.tx_lock);
- ath10k_htt_tx_dec_pending(htt, is_mgmt);
+ ath10k_htt_tx_dec_pending(htt);
+ if (is_mgmt)
+ ath10k_htt_tx_mgmt_dec_pending(htt);
spin_unlock_bh(&ar->htt.tx_lock);
}
return;
diff --git a/drivers/net/wireless/ath/ath10k/txrx.c b/drivers/net/wireless/ath/ath10k/txrx.c
index ea4d300..48e26cd 100644
--- a/drivers/net/wireless/ath/ath10k/txrx.c
+++ b/drivers/net/wireless/ath/ath10k/txrx.c
@@ -49,8 +49,8 @@ out:
spin_unlock_bh(&ar->data_lock);
}

-void ath10k_txrx_tx_unref(struct ath10k_htt *htt,
- const struct htt_tx_done *tx_done)
+int ath10k_txrx_tx_unref(struct ath10k_htt *htt,
+ const struct htt_tx_done *tx_done)
{
struct ath10k *ar = htt->ar;
struct device *dev = ar->dev;
@@ -59,7 +59,6 @@ void ath10k_txrx_tx_unref(struct ath10k_htt *htt,
struct ath10k_skb_cb *skb_cb;
struct ath10k_txq *artxq;
struct sk_buff *msdu;
- bool limit_mgmt_desc = false;

ath10k_dbg(ar, ATH10K_DBG_HTT,
"htt tx completion msdu_id %u discard %d no_ack %d success %d\n",
@@ -69,7 +68,7 @@ void ath10k_txrx_tx_unref(struct ath10k_htt *htt,
if (tx_done->msdu_id >= htt->max_num_pending_tx) {
ath10k_warn(ar, "warning: msdu_id %d too big, ignoring\n",
tx_done->msdu_id);
- return;
+ return -EINVAL;
}

spin_lock_bh(&htt->tx_lock);
@@ -78,22 +77,18 @@ void ath10k_txrx_tx_unref(struct ath10k_htt *htt,
ath10k_warn(ar, "received tx completion for invalid msdu_id: %d\n",
tx_done->msdu_id);
spin_unlock_bh(&htt->tx_lock);
- return;
+ return -ENOENT;
}

skb_cb = ATH10K_SKB_CB(msdu);
txq = skb_cb->txq;
artxq = (void *)txq->drv_priv;

- if (unlikely(skb_cb->flags & ATH10K_SKB_F_MGMT) &&
- ar->hw_params.max_probe_resp_desc_thres)
- limit_mgmt_desc = true;
-
if (txq)
artxq->num_fw_queued--;

ath10k_htt_tx_free_msdu_id(htt, tx_done->msdu_id);
- ath10k_htt_tx_dec_pending(htt, limit_mgmt_desc);
+ ath10k_htt_tx_dec_pending(htt);
if (htt->num_pending_tx == 0)
wake_up(&htt->empty_tx_wq);
spin_unlock_bh(&htt->tx_lock);
@@ -108,7 +103,7 @@ void ath10k_txrx_tx_unref(struct ath10k_htt *htt,

if (tx_done->discard) {
ieee80211_free_txskb(htt->ar->hw, msdu);
- return;
+ return 0;
}

if (!(info->flags & IEEE80211_TX_CTL_NO_ACK))
@@ -122,6 +117,7 @@ void ath10k_txrx_tx_unref(struct ath10k_htt *htt,

ieee80211_tx_status(htt->ar->hw, msdu);
/* we do not own the msdu anymore */
+ return 0;
}

struct ath10k_peer *ath10k_peer_find(struct ath10k *ar, int vdev_id,
diff --git a/drivers/net/wireless/ath/ath10k/txrx.h b/drivers/net/wireless/ath/ath10k/txrx.h
index a90e09f..e7ea1ae 100644
--- a/drivers/net/wireless/ath/ath10k/txrx.h
+++ b/drivers/net/wireless/ath/ath10k/txrx.h
@@ -19,8 +19,8 @@

#include "htt.h"

-void ath10k_txrx_tx_unref(struct ath10k_htt *htt,
- const struct htt_tx_done *tx_done);
+int ath10k_txrx_tx_unref(struct ath10k_htt *htt,
+ const struct htt_tx_done *tx_done);

struct ath10k_peer *ath10k_peer_find(struct ath10k *ar, int vdev_id,
const u8 *addr);
--
2.7.2



2016-03-08 12:40:44

by Michal Kazior

[permalink] [raw]
Subject: Re: [PATCH v3] ath10k: move mgmt descriptor limit handle under mgmt_tx

On 8 March 2016 at 12:54, Rajkumar Manoharan <[email protected]> wrote:
[...]
> +int ath10k_htt_tx_mgmt_inc_pending(struct ath10k_htt *htt, bool is_mgmt,
> + bool is_presp)
> {
> struct ath10k *ar = htt->ar;
>
> lockdep_assert_held(&htt->tx_lock);
>
> + if (!is_mgmt)
> + return 0;
> +

> if (htt->num_pending_tx >= htt->max_num_pending_tx)
> return -EBUSY;

This busy here will be hit when you use last tx slot because
tx_inc_pending() is called before tx_mgmt_inc_pending().


[...]
> skb_cb = ATH10K_SKB_CB(msdu);
> txq = skb_cb->txq;
> artxq = (void *)txq->drv_priv;
>
> - if (unlikely(skb_cb->flags & ATH10K_SKB_F_MGMT) &&
> - ar->hw_params.max_probe_resp_desc_thres)
> - limit_mgmt_desc = true;
> -

Oh wait.. I didn't pay attention before, but this looks rather ugly.
With this you will actually make the num_pending_mgmt_tx spin
endlessly upwards on firmware with HTT 3.0 (and uses TX_FRM for mgmt
tx and TX_COMPL_IND for completions), no?


Michał

2016-03-08 16:43:11

by Rajkumar Manoharan

[permalink] [raw]
Subject: Re: [PATCH v3] ath10k: move mgmt descriptor limit handle under mgmt_tx

On , Michal Kazior wrote:
> On 8 March 2016 at 13:54, Rajkumar Manoharan <[email protected]>
> wrote:
>> On , Michal Kazior wrote:
>>>
>>> On 8 March 2016 at 12:54, Rajkumar Manoharan
>>> <[email protected]>
>>> wrote:
...]
>>>>
>>>> skb_cb = ATH10K_SKB_CB(msdu);
>>>> txq = skb_cb->txq;
>>>> artxq = (void *)txq->drv_priv;
>>>>
>>>> - if (unlikely(skb_cb->flags & ATH10K_SKB_F_MGMT) &&
>>>> - ar->hw_params.max_probe_resp_desc_thres)
>>>> - limit_mgmt_desc = true;
>>>> -
>>>
>>>
>>> Oh wait.. I didn't pay attention before, but this looks rather ugly.
>>> With this you will actually make the num_pending_mgmt_tx spin
>>> endlessly upwards on firmware with HTT 3.0 (and uses TX_FRM for mgmt
>>> tx and TX_COMPL_IND for completions), no?
>>>
>> Oops.. num_pending_mgmt_tx should be incremented only for MGMT_TX.
>> Thats
>> why it is moved out of txrx_tx_unref.
>
> Hmm.. in that case I think you should change is_htt in mac_op_tx() to
> compare only against TX_HTT_MGMT (instead of both TX_HTT and
> TX_HTT_MGMT).
>
> Note, the is_mgmt should stay as it is possible for the TX_HTT_MGMT to
> be used for non-mgmt frames in some cases. This also implies you need
> to check for ATH10K_SKB_F_MGMT on the mgmt-tx-completion event as well
> (you might get to handle NullFunc there).
>
If a frame is transmitted via MGMT_TX, the reserved descriptor slots
will be
used in firmware. So irrespective of type, num_pending_mgmt_tx should
count
all frames that are transmitted via MGMT_TX to control probe resp. Here
mgmt_tx
does not mean frame type but HTT tx type (HTT_H2T_MSG_TYPE_MGMT_TX).

So ATH10K_SKB_F_MGMT check in tx-compl is not needed. As you pointed
out,
since nullfunc also uses MGMT_TX, is_mgmt should be as below. (not frame
type)

is_mgmt = (txpath == ATH10K_MAC_TX_HTT_MGMT);

-Rajkumar

2016-03-08 12:54:15

by Rajkumar Manoharan

[permalink] [raw]
Subject: Re: [PATCH v3] ath10k: move mgmt descriptor limit handle under mgmt_tx

On , Michal Kazior wrote:
> On 8 March 2016 at 12:54, Rajkumar Manoharan
> <[email protected]> wrote:
> [...]
>> +int ath10k_htt_tx_mgmt_inc_pending(struct ath10k_htt *htt, bool
>> is_mgmt,
>> + bool is_presp)
>> {
>> struct ath10k *ar = htt->ar;
>>
>> lockdep_assert_held(&htt->tx_lock);
>>
>> + if (!is_mgmt)
>> + return 0;
>> +
>
>> if (htt->num_pending_tx >= htt->max_num_pending_tx)
>> return -EBUSY;
>
> This busy here will be hit when you use last tx slot because
> tx_inc_pending() is called before tx_mgmt_inc_pending().
>
Yeah.. now this condition is not needed as
ath10k_htt_tx_mgmt_inc_pending
will be called only when tx_inc_pending succeeds. will remove this.

>
> [...]
>> skb_cb = ATH10K_SKB_CB(msdu);
>> txq = skb_cb->txq;
>> artxq = (void *)txq->drv_priv;
>>
>> - if (unlikely(skb_cb->flags & ATH10K_SKB_F_MGMT) &&
>> - ar->hw_params.max_probe_resp_desc_thres)
>> - limit_mgmt_desc = true;
>> -
>
> Oh wait.. I didn't pay attention before, but this looks rather ugly.
> With this you will actually make the num_pending_mgmt_tx spin
> endlessly upwards on firmware with HTT 3.0 (and uses TX_FRM for mgmt
> tx and TX_COMPL_IND for completions), no?
>
Oops.. num_pending_mgmt_tx should be incremented only for MGMT_TX. Thats
why it is moved out of txrx_tx_unref.

-Rajkumar

2016-03-08 13:01:29

by Michal Kazior

[permalink] [raw]
Subject: Re: [PATCH v3] ath10k: move mgmt descriptor limit handle under mgmt_tx

On 8 March 2016 at 13:54, Rajkumar Manoharan <[email protected]> wrote:
> On , Michal Kazior wrote:
>>
>> On 8 March 2016 at 12:54, Rajkumar Manoharan <[email protected]>
>> wrote:
>> [...]
>>>
>>> +int ath10k_htt_tx_mgmt_inc_pending(struct ath10k_htt *htt, bool is_mgmt,
>>> + bool is_presp)
>>> {
>>> struct ath10k *ar = htt->ar;
>>>
>>> lockdep_assert_held(&htt->tx_lock);
>>>
>>> + if (!is_mgmt)
>>> + return 0;
>>> +
>>
>>
>>> if (htt->num_pending_tx >= htt->max_num_pending_tx)
>>> return -EBUSY;
>>
>>
>> This busy here will be hit when you use last tx slot because
>> tx_inc_pending() is called before tx_mgmt_inc_pending().
>>
> Yeah.. now this condition is not needed as ath10k_htt_tx_mgmt_inc_pending
> will be called only when tx_inc_pending succeeds. will remove this.
>
>>
>> [...]
>>>
>>> skb_cb = ATH10K_SKB_CB(msdu);
>>> txq = skb_cb->txq;
>>> artxq = (void *)txq->drv_priv;
>>>
>>> - if (unlikely(skb_cb->flags & ATH10K_SKB_F_MGMT) &&
>>> - ar->hw_params.max_probe_resp_desc_thres)
>>> - limit_mgmt_desc = true;
>>> -
>>
>>
>> Oh wait.. I didn't pay attention before, but this looks rather ugly.
>> With this you will actually make the num_pending_mgmt_tx spin
>> endlessly upwards on firmware with HTT 3.0 (and uses TX_FRM for mgmt
>> tx and TX_COMPL_IND for completions), no?
>>
> Oops.. num_pending_mgmt_tx should be incremented only for MGMT_TX. Thats
> why it is moved out of txrx_tx_unref.

Hmm.. in that case I think you should change is_htt in mac_op_tx() to
compare only against TX_HTT_MGMT (instead of both TX_HTT and
TX_HTT_MGMT).

Note, the is_mgmt should stay as it is possible for the TX_HTT_MGMT to
be used for non-mgmt frames in some cases. This also implies you need
to check for ATH10K_SKB_F_MGMT on the mgmt-tx-completion event as well
(you might get to handle NullFunc there).


Michał