From: Johannes Berg <johannes.berg@xxxxxxxxx>
If a PS-poll frame is retried (but was received)
there is no way to detect that since it has no
sequence number. As a consequence, the standard
asks us to not react to PS-poll frames until the
response to one made it out (was ACKed or lost).
Implement this by adding a new station flag that
indicates whether we're sending a response, and
a new status flag that indicates we should clear
the station flag again. This requires TX status
reporting for the frame, so request that.
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
---
include/net/mac80211.h | 15 ++++++++++++++-
net/mac80211/rx.c | 10 ++++++----
net/mac80211/sta_info.c | 27 +++++++++++++++++++++++----
net/mac80211/sta_info.h | 3 +++
net/mac80211/status.c | 2 ++
5 files changed, 48 insertions(+), 9 deletions(-)
--- a/net/mac80211/rx.c 2011-09-07 15:06:19.000000000 +0200
+++ b/net/mac80211/rx.c 2011-09-07 15:06:22.000000000 +0200
@@ -1195,10 +1195,12 @@ ieee80211_rx_h_uapsd_and_pspoll(struct i
return RX_CONTINUE;
if (unlikely(ieee80211_is_pspoll(hdr->frame_control))) {
- if (!test_sta_flags(rx->sta, WLAN_STA_PS_DRIVER))
- ieee80211_sta_ps_deliver_poll_response(rx->sta);
- else
- set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
+ if (!test_sta_flags(rx->sta, WLAN_STA_POLLED)) {
+ if (!test_sta_flags(rx->sta, WLAN_STA_PS_DRIVER))
+ ieee80211_sta_ps_deliver_poll_response(rx->sta);
+ else
+ set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
+ }
/* Free PS Poll skb here instead of returning RX_DROP that would
* count as an dropped frame. */
--- a/net/mac80211/sta_info.h 2011-09-07 15:06:19.000000000 +0200
+++ b/net/mac80211/sta_info.h 2011-09-07 15:06:22.000000000 +0200
@@ -48,6 +48,8 @@
* unblocks the station.
* @WLAN_STA_SP: Station is in a service period, so don't try to
* reply to other uAPSD trigger frames.
+ * @WLAN_STA_POLLED: We're responding to a PS-Poll frame right now,
+ * don't respond to retries as well.
*/
enum ieee80211_sta_info_flags {
WLAN_STA_AUTH = 1<<0,
@@ -65,6 +67,7 @@ enum ieee80211_sta_info_flags {
WLAN_STA_PSPOLL = 1<<13,
WLAN_STA_UAPSD = 1<<14,
WLAN_STA_SP = 1<<15,
+ WLAN_STA_POLLED = 1<<16,
};
#define STA_TID_NUM 16
--- a/include/net/mac80211.h 2011-09-07 15:06:19.000000000 +0200
+++ b/include/net/mac80211.h 2011-09-07 15:06:22.000000000 +0200
@@ -360,6 +360,11 @@ struct ieee80211_bss_conf {
* when its status is reported the service period ends. For frames in
* an SP that mac80211 transmits, it is already set; for driver frames
* the driver may set this flag.
+ * @IEEE80211_TX_STATUS_PSPOLL_RESP: This packet was a response to a PS-Poll
+ * frame and thus marks the end of this PS-Poll. For frames that mac80211
+ * releases from queues it is already set; for driver queued frames the
+ * driver must set the flag and report TX status with it for a response
+ * to a PS-poll.
*
* Note: If you have to add new flags to the enumeration, then don't
* forget to update %IEEE80211_TX_TEMPORARY_FLAGS when necessary.
@@ -391,6 +396,7 @@ enum mac80211_tx_control_flags {
IEEE80211_TX_CTL_TX_OFFCHAN = BIT(25),
IEEE80211_TX_INTFL_TKIP_MIC_FAILURE = BIT(26),
IEEE80211_TX_STATUS_EOSP = BIT(27),
+ IEEE80211_TX_STATUS_PSPOLL_RESP = BIT(28),
};
#define IEEE80211_TX_CTL_STBC_SHIFT 23
@@ -406,7 +412,8 @@ enum mac80211_tx_control_flags {
IEEE80211_TX_STAT_AMPDU | IEEE80211_TX_STAT_AMPDU_NO_BACK | \
IEEE80211_TX_CTL_RATE_CTRL_PROBE | IEEE80211_TX_CTL_POLL_RESPONSE | \
IEEE80211_TX_CTL_MORE_FRAMES | IEEE80211_TX_CTL_LDPC | \
- IEEE80211_TX_CTL_STBC | IEEE80211_TX_STATUS_EOSP)
+ IEEE80211_TX_CTL_STBC | IEEE80211_TX_STATUS_EOSP | \
+ IEEE80211_TX_STATUS_PSPOLL_RESP)
/**
* enum mac80211_rate_control_flags - per-rate flags set by the
@@ -1937,6 +1944,12 @@ enum ieee80211_frame_release_type {
* the frames being released then it must still set the more-data bit in
* the frame. If the @more_data parameter is %true, then of course the
* more-data bit must always be set.
+ * In the case this is used for a PS-poll initiated release, the
+ * @num_frames parameter will always be 1 so code can be shared. In
+ * this case the driver must also set %IEEE80211_TX_STATUS_PSPOLL_RESP
+ * flag on the TX status (and must report TX status) so that the PS-poll
+ * period is properly ended. This is used to avoid sending multiple
+ * responses for a retried PS-poll frame.
* In the case this is used for uAPSD, the @num_frames parameter may be
* bigger than one, but the driver may send fewer frames (it must send
* at least one, however). In this case it is also responsible for
--- a/net/mac80211/status.c 2011-09-07 15:06:19.000000000 +0200
+++ b/net/mac80211/status.c 2011-09-07 15:06:22.000000000 +0200
@@ -254,6 +254,8 @@ void ieee80211_tx_status(struct ieee8021
if (info->flags & IEEE80211_TX_STATUS_EOSP)
clear_sta_flags(sta, WLAN_STA_SP);
+ else if (info->flags & IEEE80211_TX_STATUS_PSPOLL_RESP)
+ clear_sta_flags(sta, WLAN_STA_POLLED);
acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
if (!acked && test_sta_flags(sta, WLAN_STA_PS_STA)) {
--- a/net/mac80211/sta_info.c 2011-09-07 15:06:19.000000000 +0200
+++ b/net/mac80211/sta_info.c 2011-09-07 15:06:22.000000000 +0200
@@ -1272,8 +1272,11 @@ ieee80211_sta_ps_deliver_response(struct
hdr->frame_control |=
cpu_to_le16(IEEE80211_FCTL_MOREDATA);
- if (reason == IEEE80211_FRAME_RELEASE_UAPSD &&
- skb_queue_empty(&frames)) {
+ if (reason == IEEE80211_FRAME_RELEASE_PSPOLL) {
+ info->flags |= IEEE80211_TX_STATUS_PSPOLL_RESP |
+ IEEE80211_TX_CTL_REQ_TX_STATUS;
+ } else if (reason == IEEE80211_FRAME_RELEASE_UAPSD &&
+ skb_queue_empty(&frames)) {
/* set EOSP for the frame */
u8 *p = ieee80211_get_qos_ctl(hdr);
*p |= IEEE80211_QOS_CTL_EOSP;
@@ -1330,6 +1333,7 @@ void ieee80211_sta_ps_deliver_poll_respo
void ieee80211_sta_ps_deliver_uapsd(struct sta_info *sta)
{
+ int n_frames = sta->sta.max_sp;
u8 delivery_enabled = sta->sta.uapsd_queues;
/*
@@ -1344,8 +1348,23 @@ void ieee80211_sta_ps_deliver_uapsd(stru
/* Ohh, finally, the service period starts :-) */
set_sta_flags(sta, WLAN_STA_SP);
- ieee80211_sta_ps_deliver_response(sta, sta->sta.max_sp,
- ~delivery_enabled,
+ switch (sta->sta.max_sp) {
+ case 1:
+ n_frames = 2;
+ break;
+ case 2:
+ n_frames = 4;
+ break;
+ case 3:
+ n_frames = 6;
+ break;
+ case 0:
+ /* XXX: what is a good value? */
+ n_frames = 8;
+ break;
+ }
+
+ ieee80211_sta_ps_deliver_response(sta, n_frames, ~delivery_enabled,
IEEE80211_FRAME_RELEASE_UAPSD);
}
--
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