[PATCH 2/4] rt2x00: Decrease alignment headroom

[PATCH 2/4] rt2x00: Decrease alignment headroom

[Ivo van Doorn]

We only need 4 bytes of headroom for alignment
purposes in the RX frame. It was previously higher
for optimization purposes which are no longer
possible due to DMA mappings.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
---
diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c
index 8e86611..3ddce53 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.c
+++ b/drivers/net
/wireless/rt2x00/rt2x00queue.c
@@ -45,10 +45,11 @@ struct sk_buff *rt2x00queue_alloc_rxskb(struct rt2x00_dev *rt2x00dev,
 	frame_size = entry->queue->data_size + entry->queue->desc_size;
 
 	/*
-	 * Reserve a few bytes extra headroom to allow drivers some moving
-	 * space (e.g. for alignment), while keeping the skb aligned.
+	 * The payload should be aligned to a 4-byte boundary,
+	 * this means we need at least 3 bytes for moving the frame
+	 * into the correct offset.
 	 */
-	reserved_size = 8;
+	reserved_size = 4;
 
 	/*
 	 * Allocate skbuffer.

[PATCH 3/4] rt2x00: Use ieee80211_hw->workqueue again

[Ivo van Doorn]

Remove the rt2x00 singlethreaded workqueue and move
the link tuner and packet filter scheduled work to
the ieee80211_hw->workqueue again.
The only exception is the interface scheduled work
handler which uses the mac80211 interface iterator
under the RTNL lock. This work needs to be handled
on the kernel workqueue to prevent lockdep issues.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
---
diff --git a/drivers/net/wireless/rt2x00/rt2x00.h b/drivers/net/wireless/rt2x00/rt2x00.h
index 1b28dad..c07d9ef 100644
--- a/drivers/net/wireless/rt2x00/rt2x00.h
+++ b/drivers/net/wireless/rt2x00/rt2x00.h
@@ -787,8 +787,10 @@ struct rt2x00_dev {
 
 	/*
 	 * Scheduled work.
+	 * NOTE: intf_work will use ieee80211_iterate_active_interfaces()
+	 * which means it cannot be placed on the hw->workqueue
+	 * due to RTNL locking requirements.
 	 */
-	struct workqueue_struct *workqueue;
 	struct work_struct intf_work;
 	struct work_struct filter_work;
 
diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c
index 41b3289..8086263 100644
--- a/drivers/net/wireless/rt2x00/rt2x00dev.c
+++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
@@ -74,7 +74,7 @@ static void rt2x00lib_start_link_tuner(struct rt2x00_dev *rt2x00dev)
 
 	rt2x00lib_reset_link_tuner(rt2x00dev);
 
-	queue_delayed_work(rt2x00dev->workqueue,
+	queue_delayed_work(rt2x00dev->hw->workqueue,
 			   &rt2x00dev->link.work, LINK_TUNE_INTERVAL);
 }
 
@@ -392,7 +392,7 @@ static void rt2x00lib_link_tuner(struct work_struct *work)
 	 * Increase tuner counter, and reschedule the next link tuner run.
 	 */
 	rt2x00dev->link.count++;
-	queue_delayed_work(rt2x00dev->workqueue,
+	queue_delayed_work(rt2x00dev->hw->workqueue,
 			   &rt2x00dev->link.work, LINK_TUNE_INTERVAL);
 }
 
@@ -496,7 +496,7 @@ void rt2x00lib_beacondone(struct rt2x00_dev *rt2x00dev)
 						   rt2x00lib_beacondone_iter,
 						   rt2x00dev);
 
-	queue_work(rt2x00dev->workqueue, &rt2x00dev->intf_work);
+	schedule_work(&rt2x00dev->intf_work);
 }
 EXPORT_SYMBOL_GPL(rt2x00lib_beacondone);
 
@@ -1064,10 +1064,6 @@ int rt2x00lib_probe_dev(struct rt2x00_dev *rt2x00dev)
 	/*
 	 * Initialize configuration work.
 	 */
-	rt2x00dev->workqueue = create_singlethread_workqueue("rt2x00lib");
-	if (!rt2x00dev->workqueue)
-		goto exit;
-
 	INIT_WORK(&rt2x00dev->intf_work, rt2x00lib_intf_scheduled);
 	INIT_WORK(&rt2x00dev->filter_work, rt2x00lib_packetfilter_scheduled);
 	INIT_DELAYED_WORK(&rt2x00dev->link.work, rt2x00lib_link_tuner);
@@ -1128,13 +1124,6 @@ void rt2x00lib_remove_dev(struct rt2x00_dev *rt2x00dev)
 	rt2x00leds_unregister(rt2x00dev);
 
 	/*
-	 * Stop all queued work. Note that most tasks will already be halted
-	 * during rt2x00lib_disable_radio() and rt2x00lib_uninitialize().
-	 */
-	flush_workqueue(rt2x00dev->workqueue);
-	destroy_workqueue(rt2x00dev->workqueue);
-
-	/*
 	 * Free ieee80211_hw memory.
 	 */
 	rt2x00lib_remove_hw(rt2x00dev);
diff --git a/drivers/net/wireless/rt2x00/rt2x00mac.c b/drivers/net/wireless/rt2x00/rt2x00mac.c
index 1253da8..3a1fb6d 100644
--- a/drivers/net/wireless/rt2x00/rt2x00mac.c
+++ b/drivers/net/wireless/rt2x00/rt2x00mac.c
@@ -431,7 +431,7 @@ void rt2x00mac_configure_filter(struct ieee80211_hw *hw,
 	if (!test_bit(DRIVER_REQUIRE_SCHEDULED, &rt2x00dev->flags))
 		rt2x00dev->ops->lib->config_filter(rt2x00dev, *total_flags);
 	else
-		queue_work(rt2x00dev->workqueue, &rt2x00dev->filter_work);
+		queue_work(rt2x00dev->hw->workqueue, &rt2x00dev->filter_work);
 }
 EXPORT_SYMBOL_GPL(rt2x00mac_configure_filter);
 
@@ -512,7 +512,7 @@ void rt2x00mac_bss_info_changed(struct ieee80211_hw *hw,
 	memcpy(&intf->conf, bss_conf, sizeof(*bss_conf));
 	if (delayed) {
 		intf->delayed_flags |= delayed;
-		queue_work(rt2x00dev->workqueue, &rt2x00dev->intf_work);
+		schedule_work(&rt2x00dev->intf_work);
 	}
 	spin_unlock(&intf->lock);
 }

[PATCH 4/4] rt2x00: Report RX end time for rt2400pci

[Ivo van Doorn]

rt2400 is the only currently available rt2x00 driver which
supports reporting of the RX end time for frames.
Since mac80211 uses this information for IBSS syncing, it
is important that it is being reported.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
---
diff --git a/drivers/net/wireless/rt2x00/rt2400pci.c b/drivers/net/wireless/rt2x00/rt2400pci.c
index b3dffcf..54e2f1e 100644
--- a/drivers/net/wireless/rt2x00/rt2400pci.c
+++ b/drivers/net/wireless/rt2x00/rt2400pci.c
@@ -1091,10 +1091,12 @@ static void rt2400pci_fill_rxdone(struct queue_entry *entry,
 	u32 word0;
 	u32 word2;
 	u32 word3;
+	u32 word4;
 
 	rt2x00_desc_read(entry_priv->desc, 0, &word0);
 	rt2x00_desc_read(entry_priv->desc, 2, &word2);
 	rt2x00_desc_read(entry_priv->desc, 3, &word3);
+	rt2x00_desc_read(entry_priv->desc, 4, &word4);
 
 	if (rt2x00_get_field32(word0, RXD_W0_CRC_ERROR))
 		rxdesc->flags |= RX_FLAG_FAILED_FCS_CRC;
@@ -1106,6 +1108,7 @@ static void rt2400pci_fill_rxdone(struct queue_entry *entry,
 	 * The signal is the PLCP value, and needs to be stripped
 	 * of the preamble bit (0x08).
 	 */
+	rxdesc->timestamp = rt2x00_get_field32(word4, RXD_W4_RX_END_TIME);
 	rxdesc->signal = rt2x00_get_field32(word2, RXD_W2_SIGNAL) & ~0x08;
 	rxdesc->rssi = rt2x00_get_field32(word2, RXD_W3_RSSI) -
 	    entry->queue->rt2x00dev->rssi_offset;
diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c
index 8086263..b48c04e 100644
--- a/drivers/net/wireless/rt2x00/rt2x00dev.c
+++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
@@ -664,6 +664,7 @@ void rt2x00lib_rxdone(struct rt2x00_dev *rt2x00dev,
 
 	rt2x00dev->link.qual.rx_success++;
 
+	rx_status->mactime = rxdesc.timestamp;
 	rx_status->rate_idx = idx;
 	rx_status->qual =
 	    rt2x00lib_calculate_link_signal(rt2x00dev, rxdesc.rssi);
diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.h b/drivers/net/wireless/rt2x00/rt2x00queue.h
index 5dd9cca..8945945 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.h
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.h
@@ -146,6 +146,7 @@ enum rxdone_entry_desc_flags {
  *
  * Summary of information that has been read from the RX frame descriptor.
  *
+ * @timestamp: RX Timestamp
  * @signal: Signal of the received frame.
  * @rssi: RSSI of the received frame.
  * @size: Data size of the received frame.
@@ -154,6 +155,7 @@ enum rxdone_entry_desc_flags {
 
  */
 struct rxdone_entry_desc {
+	u64 timestamp;
 	int signal;
 	int rssi;
 	int size;

Re: [PATCH 4/4] rt2x00: Report RX end time for rt2400pci

[Johannes Berg]

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>  	rt2x00_desc_read(entry_priv->desc, 0, &word0);
>  	rt2x00_desc_read(entry_priv->desc, 2, &word2);
>  	rt2x00_desc_read(entry_priv->desc, 3, &word3);
> +	rt2x00_desc_read(entry_priv->desc, 4, &word4);
>  
>  	if (rt2x00_get_field32(word0, RXD_W0_CRC_ERROR))
>  		rxdesc->flags |= RX_FLAG_FAILED_FCS_CRC;
> @@ -1106,6 +1108,7 @@ static void rt2400pci_fill_rxdone(struct queue_entry *entry,
>  	 * The signal is the PLCP value, and needs to be stripped
>  	 * of the preamble bit (0x08).
>  	 */
> +	rxdesc->timestamp = rt2x00_get_field32(word4, RXD_W4_RX_END_TIME);

You really should extend that, like this it's going to cause trouble as
soon as it has overflowed 32 bits once.

johannes

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Re: [PATCH 4/4] rt2x00: Report RX end time for rt2400pci

[Johannes Berg]

[-- Attachment #1: Type: text/plain, Size: 1528 bytes --]

On Fri, 2008-07-04 at 14:25 +0200, Ivo van Doorn wrote:
> On Friday 04 July 2008, Johannes Berg wrote:
> > 
> > >  	rt2x00_desc_read(entry_priv->desc, 0, &word0);
> > >  	rt2x00_desc_read(entry_priv->desc, 2, &word2);
> > >  	rt2x00_desc_read(entry_priv->desc, 3, &word3);
> > > +	rt2x00_desc_read(entry_priv->desc, 4, &word4);
> > >  
> > >  	if (rt2x00_get_field32(word0, RXD_W0_CRC_ERROR))
> > >  		rxdesc->flags |= RX_FLAG_FAILED_FCS_CRC;
> > > @@ -1106,6 +1108,7 @@ static void rt2400pci_fill_rxdone(struct queue_entry *entry,
> > >  	 * The signal is the PLCP value, and needs to be stripped
> > >  	 * of the preamble bit (0x08).
> > >  	 */
> > > +	rxdesc->timestamp = rt2x00_get_field32(word4, RXD_W4_RX_END_TIME);
> > 
> > You really should extend that, like this it's going to cause trouble as
> > soon as it has overflowed 32 bits once.
> 
> Ok, but if I do the get_tsf() callback, to grab the upper 32 bytes of the timestamp,
> you will get the same problems during wraparounds, because the upper 32 bytes
> can be from _after_ the wrapround while the lower 32 bytes from the descriptor
> are still from _before_ the wraparound.

You mean bits. But no, it's not a problem, you can safely assume that
you call get_tsf() within 2^32 usecs of getting the frame (that's quite
a long time after all).

Then do something like this:

ts = word4
high32 | low32 = get_tsf()

if (ts >= low32)
  // wrapped around while we were not looking
  high32 -= 1

tsf = high32 | ts

johannes

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Re: [PATCH 4/4] rt2x00: Report RX end time for rt2400pci

[Ivo van Doorn]

On Friday 04 July 2008, Johannes Berg wrote:
> 
> >  	rt2x00_desc_read(entry_priv->desc, 0, &word0);
> >  	rt2x00_desc_read(entry_priv->desc, 2, &word2);
> >  	rt2x00_desc_read(entry_priv->desc, 3, &word3);
> > +	rt2x00_desc_read(entry_priv->desc, 4, &word4);
> >  
> >  	if (rt2x00_get_field32(word0, RXD_W0_CRC_ERROR))
> >  		rxdesc->flags |= RX_FLAG_FAILED_FCS_CRC;
> > @@ -1106,6 +1108,7 @@ static void rt2400pci_fill_rxdone(struct queue_entry *entry,
> >  	 * The signal is the PLCP value, and needs to be stripped
> >  	 * of the preamble bit (0x08).
> >  	 */
> > +	rxdesc->timestamp = rt2x00_get_field32(word4, RXD_W4_RX_END_TIME);
> 
> You really should extend that, like this it's going to cause trouble as
> soon as it has overflowed 32 bits once.

Ok, but if I do the get_tsf() callback, to grab the upper 32 bytes of the timestamp,
you will get the same problems during wraparounds, because the upper 32 bytes
can be from _after_ the wrapround while the lower 32 bytes from the descriptor
are still from _before_ the wraparound.

Ivo

Re: [PATCH 4/4] rt2x00: Report RX end time for rt2400pci

[Ivo van Doorn]

On Friday 04 July 2008, Johannes Berg wrote:
> On Fri, 2008-07-04 at 14:25 +0200, Ivo van Doorn wrote:
> > On Friday 04 July 2008, Johannes Berg wrote:
> > >=20
> > > >  	rt2x00_desc_read(entry_priv->desc, 0, &word0);
> > > >  	rt2x00_desc_read(entry_priv->desc, 2, &word2);
> > > >  	rt2x00_desc_read(entry_priv->desc, 3, &word3);
> > > > +	rt2x00_desc_read(entry_priv->desc, 4, &word4);
> > > > =20
> > > >  	if (rt2x00_get_field32(word0, RXD_W0_CRC_ERROR))
> > > >  		rxdesc->flags |=3D RX_FLAG_FAILED_FCS_CRC;
> > > > @@ -1106,6 +1108,7 @@ static void rt2400pci_fill_rxdone(struct =
queue_entry *entry,
> > > >  	 * The signal is the PLCP value, and needs to be stripped
> > > >  	 * of the preamble bit (0x08).
> > > >  	 */
> > > > +	rxdesc->timestamp =3D rt2x00_get_field32(word4, RXD_W4_RX_END=
_TIME);
> > >=20
> > > You really should extend that, like this it's going to cause trou=
ble as
> > > soon as it has overflowed 32 bits once.
> >=20
> > Ok, but if I do the get_tsf() callback, to grab the upper 32 bytes =
of the timestamp,
> > you will get the same problems during wraparounds, because the uppe=
r 32 bytes
> > can be from _after_ the wrapround while the lower 32 bytes from the=
 descriptor
> > are still from _before_ the wraparound.
>=20
> You mean bits.

Ehm yes, having a 64byte timestamp would be a bit overkill. ;)

> But no, it's not a problem, you can safely assume that=20
> you call get_tsf() within 2^32 usecs of getting the frame (that's qui=
te
> a long time after all).
>=20
> Then do something like this:
>=20
> ts =3D word4
> high32 | =EF=BB=BFlow32 =3D get_tsf()
>=20
> if (ts >=3D low32)
>   // wrapped around while we were not looking
>   high32 -=3D 1
>=20
> tsf =3D high32 | ts

Thanks, I'll update the patch.

Ivo
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[PATCH 2/4 v2] rt2x00: Decrease alignment headroom

[Ivo van Doorn]

We only need 4 bytes of headroom for alignment
purposes in the RX frame. It was previously higher
for optimization purposes which are no longer
possible due to DMA mappings.

v2: Fix patch error

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
---
diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c
index 8e86611..3ddce53 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.c
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.c
@@ -45,10 +45,11 @@ struct sk_buff *rt2x00queue_alloc_rxskb(struct rt2x00_dev *rt2x00dev,
 	frame_size = entry->queue->data_size + entry->queue->desc_size;
 
 	/*
-	 * Reserve a few bytes extra headroom to allow drivers some moving
-	 * space (e.g. for alignment), while keeping the skb aligned.
+	 * The payload should be aligned to a 4-byte boundary,
+	 * this means we need at least 3 bytes for moving the frame
+	 * into the correct offset.
 	 */
-	reserved_size = 8;
+	reserved_size = 4;
 
 	/*
 	 * Allocate skbuffer.

[PATCH 4/4 v2] rt2x00: Report RX end time for rt2400pci

[Ivo van Doorn]

rt2x00: Report RX end time for rt2400pci

rt2400 is the only currently available rt2x00 driver which
supports reporting of the RX end time for frames.
Since mac80211 uses this information for IBSS syncing, it
is important that it is being reported.

v2: Complement 32 bits of RX timestamp with upper 32bits from TSF

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
---
diff --git a/drivers/net/wireless/rt2x00/rt2400pci.c b/drivers/net/wireless/rt2x00/rt2400pci.c
index b3dffcf..ee953ca 100644
--- a/drivers/net/wireless/rt2x00/rt2400pci.c
+++ b/drivers/net/wireless/rt2x00/rt2400pci.c
@@ -1087,14 +1087,20 @@ static void rt2400pci_kick_tx_queue(struct rt2x00_dev *rt2x00dev,
 static void rt2400pci_fill_rxdone(struct queue_entry *entry,
 				  struct rxdone_entry_desc *rxdesc)
 {
+	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
 	struct queue_entry_priv_pci *entry_priv = entry->priv_data;
 	u32 word0;
 	u32 word2;
 	u32 word3;
+	u32 word4;
+	u64 tsf;
+	u32 rx_low;
+	u32 rx_high;
 
 	rt2x00_desc_read(entry_priv->desc, 0, &word0);
 	rt2x00_desc_read(entry_priv->desc, 2, &word2);
 	rt2x00_desc_read(entry_priv->desc, 3, &word3);
+	rt2x00_desc_read(entry_priv->desc, 4, &word4);
 
 	if (rt2x00_get_field32(word0, RXD_W0_CRC_ERROR))
 		rxdesc->flags |= RX_FLAG_FAILED_FCS_CRC;
@@ -1102,10 +1108,27 @@ static void rt2400pci_fill_rxdone(struct queue_entry *entry,
 		rxdesc->flags |= RX_FLAG_FAILED_PLCP_CRC;
 
 	/*
+	 * We only get the lower 32bits from the timestamp,
+	 * to get the full 64bits we must complement it with
+	 * the timestamp from get_tsf().
+	 * Note that when a wraparound of the lower 32bits
+	 * has occurred between the frame arrival and the get_tsf()
+	 * call, we must decrease the higher 32bits with 1 to get
+	 * to correct value.
+	 */
+	tsf = rt2x00dev->ops->hw->get_tsf(rt2x00dev->hw);
+	rx_low = rt2x00_get_field32(word4, RXD_W4_RX_END_TIME);
+	rx_high = upper_32_bits(tsf);
+
+	if ((u32)tsf <= rx_low)
+		rx_high--;
+
+	/*
 	 * Obtain the status about this packet.
 	 * The signal is the PLCP value, and needs to be stripped
 	 * of the preamble bit (0x08).
 	 */
+	rxdesc->timestamp = ((u64)rx_high << 32) | rx_low;
 	rxdesc->signal = rt2x00_get_field32(word2, RXD_W2_SIGNAL) & ~0x08;
 	rxdesc->rssi = rt2x00_get_field32(word2, RXD_W3_RSSI) -
 	    entry->queue->rt2x00dev->rssi_offset;
diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c
index 8086263..b48c04e 100644
--- a/drivers/net/wireless/rt2x00/rt2x00dev.c
+++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
@@ -664,6 +664,7 @@ void rt2x00lib_rxdone(struct rt2x00_dev *rt2x00dev,
 
 	rt2x00dev->link.qual.rx_success++;
 
+	rx_status->mactime = rxdesc.timestamp;
 	rx_status->rate_idx = idx;
 	rx_status->qual =
 	    rt2x00lib_calculate_link_signal(rt2x00dev, rxdesc.rssi);
diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.h b/drivers/net/wireless/rt2x00/rt2x00queue.h
index 5dd9cca..8945945 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.h
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.h
@@ -146,6 +146,7 @@ enum rxdone_entry_desc_flags {
  *
  * Summary of information that has been read from the RX frame descriptor.
  *
+ * @timestamp: RX Timestamp
  * @signal: Signal of the received frame.
  * @rssi: RSSI of the received frame.
  * @size: Data size of the received frame.
@@ -154,6 +155,7 @@ enum rxdone_entry_desc_flags {
 
  */
 struct rxdone_entry_desc {
+	u64 timestamp;
 	int signal;
 	int rssi;
 	int size;