[PATCH 1/3] cfg80211: Add antenna availability information

[PATCH 1/3] cfg80211: Add antenna availability information

[Bruno Randolf]

Add a field to wiphy for the hardware to report the availble antennas for
configuration. Only if this is set to something bigger than zero, will the
anntenna configuration ops be executed.

Allthough this could be a simple number of antennas, I defined it as a bitmap
of antennas which are available for configuration, since it's more consistent
with the rest of the antenna API and there could be cases where the
hardware allows only configuration of certain antennas. As it does not make
much of a difference in size or normal usage, I think it's better to be able to
support this, in case the need arises.

Signed-off-by: Bruno Randolf <br1@einfach.org>
---
 include/net/cfg80211.h |    5 +++++
 net/wireless/nl80211.c |    4 ++--
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 589c4b1..d0d4af8 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1442,6 +1442,9 @@ struct ieee80211_txrx_stypes {
  * @mgmt_stypes: bitmasks of frame subtypes that can be subscribed to or
  *	transmitted through nl80211, points to an array indexed by interface
  *	type
+ *
+ * @available_antennas: bitmap of antennas which are available to configure.
+ *	antenna configuration commands will be rejected unless this is set.
  */
 struct wiphy {
 	/* assign these fields before you register the wiphy */
@@ -1481,6 +1484,8 @@ struct wiphy {
 
 	u8 max_num_pmkids;
 
+	u32 available_antennas;
+
 	/* If multiple wiphys are registered and you're handed e.g.
 	 * a regular netdev with assigned ieee80211_ptr, you won't
 	 * know whether it points to a wiphy your driver has registered
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 45fe06d..4854df9 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -547,7 +547,7 @@ static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags,
 	if (dev->wiphy.flags & WIPHY_FLAG_CONTROL_PORT_PROTOCOL)
 		NLA_PUT_FLAG(msg, NL80211_ATTR_CONTROL_PORT_ETHERTYPE);
 
-	if (dev->ops->get_antenna) {
+	if (dev->wiphy.available_antennas && dev->ops->get_antenna) {
 		u32 tx_ant = 0, rx_ant = 0;
 		int res;
 		res = dev->ops->get_antenna(&dev->wiphy, &tx_ant, &rx_ant);
@@ -1044,7 +1044,7 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 	if (info->attrs[NL80211_ATTR_WIPHY_ANTENNA_TX] &&
 	    info->attrs[NL80211_ATTR_WIPHY_ANTENNA_RX]) {
 		u32 tx_ant, rx_ant;
-		if (!rdev->ops->set_antenna) {
+		if (!rdev->wiphy.available_antennas || !rdev->ops->set_antenna) {
 			result = -EOPNOTSUPP;
 			goto bad_res;
 		}

[PATCH 2/3] nl80211: Export available antennas

[Bruno Randolf]

Signed-off-by: Bruno Randolf <br1@einfach.org>
---
 include/linux/nl80211.h |    5 +++++
 net/wireless/nl80211.c  |    2 ++
 2 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index 68fc25f..5f64fd6 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -833,6 +833,9 @@ enum nl80211_commands {
  *	the hardware should not be configured to receive on this antenna.
  *	For a more detailed descripton see @NL80211_ATTR_WIPHY_ANTENNA_TX.
  *
+ * @NL80211_ATTR_WIPHY_ANTENNA_AVAIL: Bitmap of antennas which are available for
+ *	configuration via the above parameters.
+ *
  * @NL80211_ATTR_MCAST_RATE: Multicast tx rate (in 100 kbps) for IBSS
  *
  * @NL80211_ATTR_OFFCHANNEL_TX_OK: For management frame TX, the frame may be
@@ -1017,6 +1020,8 @@ enum nl80211_attrs {
 
 	NL80211_ATTR_OFFCHANNEL_TX_OK,
 
+	NL80211_ATTR_WIPHY_ANTENNA_AVAIL,
+
 	/* add attributes here, update the policy in nl80211.c */
 
 	__NL80211_ATTR_AFTER_LAST,
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 4854df9..1d49d75 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -555,6 +555,8 @@ static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags,
 			NLA_PUT_U32(msg, NL80211_ATTR_WIPHY_ANTENNA_TX, tx_ant);
 			NLA_PUT_U32(msg, NL80211_ATTR_WIPHY_ANTENNA_RX, rx_ant);
 		}
+		NLA_PUT_U32(msg, NL80211_ATTR_WIPHY_ANTENNA_AVAIL,
+			    dev->wiphy.available_antennas);
 	}
 
 	nl_modes = nla_nest_start(msg, NL80211_ATTR_SUPPORTED_IFTYPES);

[PATCH 3/3] ath5k: Set available antenna information for cfg80211

[Bruno Randolf]

Signed-off-by: Bruno Randolf <br1@einfach.org>
---
 drivers/net/wireless/ath/ath5k/base.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/drivers/net/wireless/ath/ath5k/base.c b/drivers/net/wireless/ath/ath5k/base.c
index d74ee0d..e648467 100644
--- a/drivers/net/wireless/ath/ath5k/base.c
+++ b/drivers/net/wireless/ath/ath5k/base.c
@@ -2350,6 +2350,8 @@ ath5k_init_softc(struct ath5k_softc *sc, const struct ath_bus_ops *bus_ops)
 		BIT(NL80211_IFTYPE_ADHOC) |
 		BIT(NL80211_IFTYPE_MESH_POINT);
 
+	hw->wiphy->available_antennas = 0x3; /* both can be configured */
+
 	hw->extra_tx_headroom = 2;
 	hw->channel_change_time = 5000;
 

Re: [PATCH 2/3] nl80211: Export available antennas

[Johannes Berg]

On Mon, 2010-12-06 at 12:45 +0900, Bruno Randolf wrote:

> +		NLA_PUT_U32(msg, NL80211_ATTR_WIPHY_ANTENNA_AVAIL,
> +			    dev->wiphy.available_antennas);

I think you should not advertise this unless it's non-zero, and unless
also the set/get callbacks are available.

Similarly, I think you shouldn't advertise the set/get CMDs when the
available antennas aren't set.

Finally, you should check for nl80211 that the given tx/rx masks fall
into the available antennas mask.

johannes

Re: [PATCH 2/3] nl80211: Export available antennas

[Bruno Randolf]

On Mon December 6 2010 17:17:33 Johannes Berg wrote:
> On Mon, 2010-12-06 at 12:45 +0900, Bruno Randolf wrote:
> > +		NLA_PUT_U32(msg, NL80211_ATTR_WIPHY_ANTENNA_AVAIL,
> > +			    dev->wiphy.available_antennas);
> 
> I think you should not advertise this unless it's non-zero, and unless
> also the set/get callbacks are available.

I don't. Please check the context of this patch, esp patch 1. of this series.

> Similarly, I think you shouldn't advertise the set/get CMDs when the
> available antennas aren't set.

There are no set/get commands for antennas since you preferred putting it into 
wiphy info.

> Finally, you should check for nl80211 that the given tx/rx masks fall
> into the available antennas mask.

Allright, I can do that. Would you prefer to reject the command in this case 
or just apply the available mask?

bruno

Re: [PATCH 2/3] nl80211: Export available antennas

[Johannes Berg]

On Mon, 2010-12-06 at 17:30 +0900, Bruno Randolf wrote:
> On Mon December 6 2010 17:17:33 Johannes Berg wrote:
> > On Mon, 2010-12-06 at 12:45 +0900, Bruno Randolf wrote:
> > > +		NLA_PUT_U32(msg, NL80211_ATTR_WIPHY_ANTENNA_AVAIL,
> > > +			    dev->wiphy.available_antennas);
> > 
> > I think you should not advertise this unless it's non-zero, and unless
> > also the set/get callbacks are available.
> 
> I don't. Please check the context of this patch, esp patch 1. of this series.

Ah, indeed, the context overlap was lost on me.

> > Similarly, I think you shouldn't advertise the set/get CMDs when the
> > available antennas aren't set.
> 
> There are no set/get commands for antennas since you preferred putting it into 
> wiphy info.

Oops. Forgot all about that, sorry!

> > Finally, you should check for nl80211 that the given tx/rx masks fall
> > into the available antennas mask.
> 
> Allright, I can do that. Would you prefer to reject the command in this case 
> or just apply the available mask?

I'd reject it, since userspace could have checked whether it was valid.

johannes

Re: [PATCH 2/3] nl80211: Export available antennas

[Bruno Randolf]

On Mon December 6 2010 17:33:20 Johannes Berg wrote:
> > > Finally, you should check for nl80211 that the given tx/rx masks fall
> > > into the available antennas mask.
> > 
> > Allright, I can do that. Would you prefer to reject the command in this
> > case or just apply the available mask?
> 
> I'd reject it, since userspace could have checked whether it was valid.

Hmm, been thinking about it: the "iw phyX set antenna all" will not work in 
that case. Unless we get the available antennas before setting "all" in iw, 
which seems like a lot of overhead...

Alternatively we can either apply the mask in mac80211 or just hand the 
antenna masks as they are to the driver, which is what we do now.

I think either way it's not a big deal.

bruno

Re: [PATCH 2/3] nl80211: Export available antennas

[Johannes Berg]

On Tue, 2010-12-07 at 11:17 +0900, Bruno Randolf wrote:
> On Mon December 6 2010 17:33:20 Johannes Berg wrote:
> > > > Finally, you should check for nl80211 that the given tx/rx masks fall
> > > > into the available antennas mask.
> > > 
> > > Allright, I can do that. Would you prefer to reject the command in this
> > > case or just apply the available mask?
> > 
> > I'd reject it, since userspace could have checked whether it was valid.
> 
> Hmm, been thinking about it: the "iw phyX set antenna all" will not work in 
> that case. Unless we get the available antennas before setting "all" in iw, 
> which seems like a lot of overhead...
> 
> Alternatively we can either apply the mask in mac80211 or just hand the 
> antenna masks as they are to the driver, which is what we do now.

I think I'd be more happy with treating ~0 as special (which it is
anyway, apply the mask to it) and allowing that to not match the mask.
That way, the most common errors still don't have to be handled in the
driver.

johannes

Re: [PATCH 2/3] nl80211: Export available antennas

[Bruno Randolf]

On Tue December 7 2010 18:35:40 Johannes Berg wrote:
> On Tue, 2010-12-07 at 11:17 +0900, Bruno Randolf wrote:
> > On Mon December 6 2010 17:33:20 Johannes Berg wrote:
> > > > > Finally, you should check for nl80211 that the given tx/rx masks
> > > > > fall into the available antennas mask.
> > > > 
> > > > Allright, I can do that. Would you prefer to reject the command in
> > > > this case or just apply the available mask?
> > > 
> > > I'd reject it, since userspace could have checked whether it was valid.
> > 
> > Hmm, been thinking about it: the "iw phyX set antenna all" will not work
> > in that case. Unless we get the available antennas before setting "all"
> > in iw, which seems like a lot of overhead...
> > 
> > Alternatively we can either apply the mask in mac80211 or just hand the
> > antenna masks as they are to the driver, which is what we do now.
> 
> I think I'd be more happy with treating ~0 as special (which it is
> anyway, apply the mask to it) and allowing that to not match the mask.
> That way, the most common errors still don't have to be handled in the
> driver.

Allright. Sent a patch for this.

bruno

[PATCH 2/3] nl80211: Export available antennas

[Bruno Randolf]

Export the information which antennas are available for configuration as TX or
RX antennas via nl80211.

Signed-off-by: Bruno Randolf <br1@einfach.org>

---

v3:	rebased and updated for separate RX and TX availablility
v2:	rebased
---
 include/linux/nl80211.h |    9 +++++++++
 net/wireless/nl80211.c  |    5 +++++
 2 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index 1cee56b..a6e1ec5 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -844,6 +844,12 @@ enum nl80211_commands {
  *	the hardware should not be configured to receive on this antenna.
  *	For a more detailed descripton see @NL80211_ATTR_WIPHY_ANTENNA_TX.
  *
+ * @NL80211_ATTR_WIPHY_ANTENNA_AVAIL_TX: Bitmap of antennas which are available
+ *	for configuration as TX antennas via the above parameters.
+ *
+ * @NL80211_ATTR_WIPHY_ANTENNA_AVAIL_RX: Bitmap of antennas which are available
+ *	for configuration as RX antennas via the above parameters.
+ *
  * @NL80211_ATTR_MCAST_RATE: Multicast tx rate (in 100 kbps) for IBSS
  *
  * @NL80211_ATTR_OFFCHANNEL_TX_OK: For management frame TX, the frame may be
@@ -1040,6 +1046,9 @@ enum nl80211_attrs {
 
 	NL80211_ATTR_MAX_REMAIN_ON_CHANNEL_DURATION,
 
+	NL80211_ATTR_WIPHY_ANTENNA_AVAIL_TX,
+	NL80211_ATTR_WIPHY_ANTENNA_AVAIL_RX,
+
 	/* add attributes here, update the policy in nl80211.c */
 
 	__NL80211_ATTR_AFTER_LAST,
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 087397b..ad3ca7d 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -605,6 +605,11 @@ static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags,
 	if (dev->wiphy.flags & WIPHY_FLAG_CONTROL_PORT_PROTOCOL)
 		NLA_PUT_FLAG(msg, NL80211_ATTR_CONTROL_PORT_ETHERTYPE);
 
+	NLA_PUT_U32(msg, NL80211_ATTR_WIPHY_ANTENNA_AVAIL_TX,
+		    dev->wiphy.available_antennas_tx);
+	NLA_PUT_U32(msg, NL80211_ATTR_WIPHY_ANTENNA_AVAIL_RX,
+		    dev->wiphy.available_antennas_rx);
+
 	if ((dev->wiphy.available_antennas_tx ||
 	     dev->wiphy.available_antennas_rx) && dev->ops->get_antenna) {
 		u32 tx_ant = 0, rx_ant = 0;