2010-08-25 14:14:43

by Vivek Natarajan

[permalink] [raw]
Subject: [PATCH 1/2] ath9k: Fix for throughput issue in Intel Pinetrail platform.

Trigger the generic timer interrupt frequently as a workaround
to improve the throughput in C3 state with the Intel Pinetrail
platform.

Signed-off-by: Vivek Natarajan <[email protected]>
---
drivers/net/wireless/ath/ath9k/ath9k.h | 21 ++++++++++++++++++++-
drivers/net/wireless/ath/ath9k/debug.c | 8 ++++++--
drivers/net/wireless/ath/ath9k/gpio.c | 4 ++--
drivers/net/wireless/ath/ath9k/hw.c | 6 ++++--
drivers/net/wireless/ath/ath9k/init.c | 23 +++++++++++++++++++++++
drivers/net/wireless/ath/ath9k/main.c | 9 ++++++++-
drivers/net/wireless/ath/ath9k/xmit.c | 29 +++++++++++++++++++++++++++++
7 files changed, 92 insertions(+), 8 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index f0197a6..841760c 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -31,6 +31,7 @@
*/

struct ath_node;
+extern unsigned int c3_war_timer;

/* Macro to expand scalars to 64-bit objects */

@@ -241,6 +242,7 @@ struct ath_buf {
dma_addr_t bf_daddr; /* physical addr of desc */
dma_addr_t bf_buf_addr; /* physical addr of data buffer */
bool bf_stale;
+ bool bf_isdata;
bool bf_isnullfunc;
bool bf_tx_aborted;
u16 bf_flags;
@@ -597,8 +599,23 @@ struct ath_softc {
struct ath_btcoex btcoex;

struct ath_descdma txsdma;
+
+ atomic_t pending_tx_data_frames;
+ bool fifo_underrun;
+ bool c3_timer_active;
+ spinlock_t c3_lock;
+ struct ath_gen_timer *c3_hw_timer;
};

+static inline void stop_c3_hw_timer(struct ath_softc *sc)
+{
+ if (c3_war_timer) {
+ spin_lock(&sc->c3_lock);
+ sc->c3_timer_active = false;
+ spin_unlock(&sc->c3_lock);
+ }
+}
+
struct ath_wiphy {
struct ath_softc *sc; /* shared for all virtual wiphys */
struct ieee80211_hw *hw;
@@ -685,5 +702,7 @@ bool ath_mac80211_start_queue(struct ath_softc *sc, u16 skb_queue);

void ath_start_rfkill_poll(struct ath_softc *sc);
extern void ath9k_rfkill_poll_state(struct ieee80211_hw *hw);
-
+void ath9k_gen_timer_start(struct ath_hw *ah, struct ath_gen_timer *timer,
+ u32 timer_next, u32 timer_period);
+void ath9k_gen_timer_stop(struct ath_hw *ah, struct ath_gen_timer *timer);
#endif /* ATH9K_H */
diff --git a/drivers/net/wireless/ath/ath9k/debug.c b/drivers/net/wireless/ath/ath9k/debug.c
index 54aae93..4e4c77d 100644
--- a/drivers/net/wireless/ath/ath9k/debug.c
+++ b/drivers/net/wireless/ath/ath9k/debug.c
@@ -693,10 +693,14 @@ void ath_debug_stat_tx(struct ath_softc *sc, struct ath_txq *txq,
TX_STAT_INC(txq->axq_qnum, timer_exp);
if (ts->ts_flags & ATH9K_TX_DESC_CFG_ERR)
TX_STAT_INC(txq->axq_qnum, desc_cfg_err);
- if (ts->ts_flags & ATH9K_TX_DATA_UNDERRUN)
+ if (ts->ts_flags & ATH9K_TX_DATA_UNDERRUN) {
TX_STAT_INC(txq->axq_qnum, data_underrun);
- if (ts->ts_flags & ATH9K_TX_DELIM_UNDERRUN)
+ sc->fifo_underrun = 1;
+ }
+ if (ts->ts_flags & ATH9K_TX_DELIM_UNDERRUN) {
TX_STAT_INC(txq->axq_qnum, delim_underrun);
+ sc->fifo_underrun = 1;
+ }
}

static const struct file_operations fops_xmit = {
diff --git a/drivers/net/wireless/ath/ath9k/gpio.c b/drivers/net/wireless/ath/ath9k/gpio.c
index 4a9a68b..ca8311b 100644
--- a/drivers/net/wireless/ath/ath9k/gpio.c
+++ b/drivers/net/wireless/ath/ath9k/gpio.c
@@ -251,7 +251,7 @@ static void ath_detect_bt_priority(struct ath_softc *sc)
}
}

-static void ath9k_gen_timer_start(struct ath_hw *ah,
+void ath9k_gen_timer_start(struct ath_hw *ah,
struct ath_gen_timer *timer,
u32 timer_next,
u32 timer_period)
@@ -265,7 +265,7 @@ static void ath9k_gen_timer_start(struct ath_hw *ah,
}
}

-static void ath9k_gen_timer_stop(struct ath_hw *ah, struct ath_gen_timer *timer)
+void ath9k_gen_timer_stop(struct ath_hw *ah, struct ath_gen_timer *timer)
{
struct ath_gen_timer_table *timer_table = &ah->hw_gen_timers;

diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index 3384ca1..c69642a 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -2763,7 +2763,8 @@ void ath_gen_timer_isr(struct ath_hw *ah)
BUG_ON(!timer);
ath_print(common, ATH_DBG_HWTIMER,
"TSF overflow for Gen timer %d\n", index);
- timer->overflow(timer->arg);
+ if (timer->overflow)
+ timer->overflow(timer->arg);
}

while (trigger_mask) {
@@ -2772,7 +2773,8 @@ void ath_gen_timer_isr(struct ath_hw *ah)
BUG_ON(!timer);
ath_print(common, ATH_DBG_HWTIMER,
"Gen timer[%d] trigger\n", index);
- timer->trigger(timer->arg);
+ if (timer->trigger)
+ timer->trigger(timer->arg);
}
}
EXPORT_SYMBOL(ath_gen_timer_isr);
diff --git a/drivers/net/wireless/ath/ath9k/init.c b/drivers/net/wireless/ath/ath9k/init.c
index 243c177..c3ae6f9 100644
--- a/drivers/net/wireless/ath/ath9k/init.c
+++ b/drivers/net/wireless/ath/ath9k/init.c
@@ -18,6 +18,8 @@

#include "ath9k.h"

+#define ATH_TIMER_INDEX(i) ((debruijn32 << i) >> 27)
+
static char *dev_info = "ath9k";

MODULE_AUTHOR("Atheros Communications");
@@ -37,6 +39,9 @@ int led_blink = 1;
module_param_named(blink, led_blink, int, 0444);
MODULE_PARM_DESC(blink, "Enable LED blink on activity");

+unsigned int c3_war_timer;
+module_param_named(c3_timer, c3_war_timer, uint, 0);
+
/* We use the hw_value as an index into our private channel structure */

#define CHAN2G(_freq, _idx) { \
@@ -597,6 +602,21 @@ static int ath9k_init_softc(u16 devid, struct ath_softc *sc, u16 subsysid,
ath9k_init_channels_rates(sc);
ath9k_init_misc(sc);

+ if (c3_war_timer) {
+ int i;
+ for (i = 0; i < 32; i++)
+ sc->sc_ah->hw_gen_timers.gen_timer_index
+ [ATH_TIMER_INDEX(i)] = i;
+
+ sc->c3_hw_timer = ath_gen_timer_alloc(ah, NULL,
+ NULL,
+ (void *)sc,
+ AR_FIRST_NDP_TIMER + 1);
+ sc->c3_timer_active = 0;
+ atomic_set(&sc->pending_tx_data_frames, 0);
+ sc->fifo_underrun = 0;
+ spin_lock_init(&sc->c3_lock);
+ }
return 0;

err_btcoex:
@@ -755,6 +775,9 @@ static void ath9k_deinit_softc(struct ath_softc *sc)
sc->sc_ah->btcoex_hw.scheme == ATH_BTCOEX_CFG_3WIRE)
ath_gen_timer_free(sc->sc_ah, sc->btcoex.no_stomp_timer);

+ if (c3_war_timer && sc->c3_hw_timer)
+ ath_gen_timer_free(sc->sc_ah, sc->c3_hw_timer);
+
for (i = 0; i < ATH9K_NUM_TX_QUEUES; i++)
if (ATH_TXQ_SETUP(sc, i))
ath_tx_cleanupq(sc, &sc->tx.txq[i]);
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 1165f90..c9f1c86 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -244,6 +244,8 @@ int ath_set_channel(struct ath_softc *sc, struct ieee80211_hw *hw,
}
spin_unlock_bh(&sc->sc_resetlock);

+ stop_c3_hw_timer(sc);
+
if (ath_startrecv(sc) != 0) {
ath_print(common, ATH_DBG_FATAL,
"Unable to restart recv logic\n");
@@ -617,7 +619,7 @@ void ath9k_tasklet(unsigned long data)
sc->ps_flags |= PS_WAIT_FOR_BEACON | PS_BEACON_SYNC;
}

- if (ah->btcoex_hw.scheme == ATH_BTCOEX_CFG_3WIRE)
+ if (c3_war_timer || ah->btcoex_hw.scheme == ATH_BTCOEX_CFG_3WIRE)
if (status & ATH9K_INT_GENTIMER)
ath_gen_timer_isr(sc->sc_ah);

@@ -854,6 +856,7 @@ void ath_radio_enable(struct ath_softc *sc, struct ieee80211_hw *hw)
}
spin_unlock_bh(&sc->sc_resetlock);

+ stop_c3_hw_timer(sc);
ath_update_txpow(sc);
if (ath_startrecv(sc) != 0) {
ath_print(common, ATH_DBG_FATAL,
@@ -914,6 +917,8 @@ void ath_radio_disable(struct ath_softc *sc, struct ieee80211_hw *hw)
}
spin_unlock_bh(&sc->sc_resetlock);

+ stop_c3_hw_timer(sc);
+
ath9k_hw_phy_disable(ah);
ath9k_hw_configpcipowersave(ah, 1, 1);
ath9k_ps_restore(sc);
@@ -944,6 +949,8 @@ int ath_reset(struct ath_softc *sc, bool retry_tx)
"Unable to reset hardware; reset status %d\n", r);
spin_unlock_bh(&sc->sc_resetlock);

+ stop_c3_hw_timer(sc);
+
if (ath_startrecv(sc) != 0)
ath_print(common, ATH_DBG_FATAL,
"Unable to start recv logic\n");
diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 457f076..77e787a 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -1169,6 +1169,8 @@ void ath_drain_all_txq(struct ath_softc *sc, bool retry_tx)
"Unable to reset hardware; reset status %d\n",
r);
spin_unlock_bh(&sc->sc_resetlock);
+
+ stop_c3_hw_timer(sc);
}

for (i = 0; i < ATH9K_NUM_TX_QUEUES; i++) {
@@ -1272,6 +1274,18 @@ static void ath_tx_txqaddbuf(struct ath_softc *sc, struct ath_txq *txq,
ath_print(common, ATH_DBG_QUEUE,
"qnum: %d, txq depth: %d\n", txq->axq_qnum, txq->axq_depth);

+ if (c3_war_timer && bf->bf_isdata &&
+ sc->fifo_underrun && sc->c3_hw_timer) {
+ spin_lock(&sc->c3_lock);
+ if (!sc->c3_timer_active) {
+ sc->c3_timer_active = 1;
+ ath9k_gen_timer_start(ah, sc->c3_hw_timer,
+ ath9k_hw_gettsf32(sc->sc_ah),
+ c3_war_timer);
+ }
+ spin_unlock(&sc->c3_lock);
+ }
+
if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
if (txq->axq_depth >= ATH_TXFIFO_DEPTH) {
list_splice_tail_init(head, &txq->txq_fifo_pending);
@@ -1668,6 +1682,7 @@ static int ath_tx_setup_buffer(struct ieee80211_hw *hw, struct ath_buf *bf,
return -ENOMEM;
}

+ bf->bf_isdata = ieee80211_is_data(fc);
bf->bf_buf_addr = bf->bf_dmacontext;

/* tag if this is a nullfunc frame to enable PS when AP acks it */
@@ -1717,6 +1732,9 @@ static void ath_tx_start_dma(struct ath_softc *sc, struct ath_buf *bf,
bf->bf_buf_addr,
txctl->txq->axq_qnum);

+ if (c3_war_timer && bf->bf_isdata)
+ atomic_inc(&sc->pending_tx_data_frames);
+
if (bf->bf_state.bfs_paprd)
ar9003_hw_set_paprd_txdesc(ah, ds, bf->bf_state.bfs_paprd);

@@ -1942,6 +1960,17 @@ static void ath_tx_complete_buf(struct ath_softc *sc, struct ath_buf *bf,

dma_unmap_single(sc->dev, bf->bf_dmacontext, skb->len, DMA_TO_DEVICE);

+ if (c3_war_timer && bf->bf_isdata) {
+ atomic_dec(&sc->pending_tx_data_frames);
+ spin_lock(&sc->c3_lock);
+ if (!atomic_read(&sc->pending_tx_data_frames) &&
+ sc->c3_timer_active) {
+ ath9k_gen_timer_stop(sc->sc_ah, sc->c3_hw_timer);
+ sc->c3_timer_active = false;
+ }
+ spin_unlock(&sc->c3_lock);
+ }
+
if (bf->bf_state.bfs_paprd) {
if (time_after(jiffies,
bf->bf_state.bfs_paprd_timestamp +
--
1.6.3.3




2010-08-25 14:14:43

by Vivek Natarajan

[permalink] [raw]
Subject: [PATCH 2/2] ath9k: Change the default LED pattern.

All major Atheros customers require the led to be in continuous
ON state rather than the blinking pattern.

Signed-off-by: Vivek Natarajan <[email protected]>
---
drivers/net/wireless/ath/ath9k/init.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/init.c b/drivers/net/wireless/ath/ath9k/init.c
index c3ae6f9..5912aec 100644
--- a/drivers/net/wireless/ath/ath9k/init.c
+++ b/drivers/net/wireless/ath/ath9k/init.c
@@ -35,7 +35,7 @@ int modparam_nohwcrypt;
module_param_named(nohwcrypt, modparam_nohwcrypt, int, 0444);
MODULE_PARM_DESC(nohwcrypt, "Disable hardware encryption");

-int led_blink = 1;
+int led_blink;
module_param_named(blink, led_blink, int, 0444);
MODULE_PARM_DESC(blink, "Enable LED blink on activity");

--
1.6.3.3



2010-08-25 15:01:10

by Vivek Natarajan

[permalink] [raw]
Subject: Re: [PATCH 1/2] ath9k: Fix for throughput issue in Intel Pinetrail platform.

On Wed, Aug 25, 2010 at 7:52 PM, Johannes Berg
<[email protected]> wrote:
> On Wed, 2010-08-25 at 19:34 +0530, Vivek Natarajan wrote:
>> Trigger the generic timer interrupt frequently as a workaround
>> to improve the throughput in C3 state with the Intel Pinetrail
>> platform.
>
> This seems an awfully lot like a DMA problem with C3 states or something
> like that? It seems like you should do something like this:
>
> ? ? ? ?pm_qos_add_request(&ipw2100_pm_qos_req, PM_QOS_CPU_DMA_LATENCY,
> ? ? ? ? ? ? ? ? ? ? ? ? ? PM_QOS_DEFAULT_VALUE);

Thanks a lot for your insights. We will try it out.

Vivek.

2010-08-25 14:59:40

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH 1/2] ath9k: Fix for throughput issue in Intel Pinetrail platform.

On Wed, 2010-08-25 at 19:34 +0530, Vivek Natarajan wrote:
> Trigger the generic timer interrupt frequently as a workaround
> to improve the throughput in C3 state with the Intel Pinetrail
> platform.

This seems an awfully lot like a DMA problem with C3 states or something
like that? It seems like you should do something like this:

pm_qos_add_request(&ipw2100_pm_qos_req, PM_QOS_CPU_DMA_LATENCY,
PM_QOS_DEFAULT_VALUE);

(taken from ipw2100)

johannes



2010-08-25 14:22:38

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH 1/2] ath9k: Fix for throughput issue in Intel Pinetrail platform.

On Wed, 2010-08-25 at 19:34 +0530, Vivek Natarajan wrote:
> Trigger the generic timer interrupt frequently as a workaround
> to improve the throughput in C3 state with the Intel Pinetrail
> platform.

This seems an awfully lot like a DMA problem with C3 states or something
like that? It seems like you should do something like this:

pm_qos_add_request(&ipw2100_pm_qos_req, PM_QOS_CPU_DMA_LATENCY,
PM_QOS_DEFAULT_VALUE);

(taken from ipw2100)

johannes