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First cut at attempting to buffer frames until we see a beacon.

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The iwn(4) firmware forgets most of its channel state after an RXON
command.  This means that any beacons its seen on passive 5GHz channels
are forgotten upon an association/authorisation request.
This unfortuantely means that 5GHz association almost always fails -
the assoc and/or auth frames are dropped with a status of "passive
channel, haven't seen a beacon yet." (0x90.)

So:

* add an xmit queue, global, to buffer frames
* modify the xmit path to use the mbuf tag from net80211
  to specify raw frame details
* buffer xmit frames from both raw and non-raw paths
* if a beacon is seen in the RX path, schedule a taskqueue to
  send said frames and un-buffer things.
* flush frames during state change back to INIT, or NIC
  down/up/detach.

This isn't the final shape I'd like this to be in but it certainly
is better than 5GHz "not working at all".

Tested:

* Intel 5100, STA mode (before spilling coffee)
* Intel 5300, STA mode (after spilling coffee)

Story:

* This has been bugging me at work for months, which I just
  worked around by throwing an ath(4) into my Lenovo T400 cardbus
  slot.

* Our ops director discovered indeed FreeBSD runs well on the
  Lenovo T420p, except for that pesky 5GHz thing.  So now developers
  also can have a T420p running FreeBSD to do work with.
  Their #1 feedback to me - "boy it'd be nice if 5GHz wifi worked."

* .. then, I was at NANOG but stuck with 5GHz only wifi and no ath(4)
  NIC to put in a laptop - and I snapped.

Thus, the reason this is actually work related.

MFC after:	2 weeks
Sponsored by:	Norse Corp, Inc.
This commit is contained in:
Adrian Chadd 2015-06-19 01:44:17 +00:00
parent bcb23c1e09
commit 3233d0c654
2 changed files with 151 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

140
sys/dev/iwn/if_iwn.c
View File

@ -232,6 +232,7 @@ static int iwn_tx_data(struct iwn_softc *, struct mbuf *,
static int iwn_tx_data_raw(struct iwn_softc *, struct mbuf *,
struct ieee80211_node *,
const struct ieee80211_bpf_params *params);
static void iwn_xmit_task(void *arg0, int pending);
static int iwn_raw_xmit(struct ieee80211_node *, struct mbuf *,
const struct ieee80211_bpf_params *);
static void iwn_start(struct ifnet *);
@ -682,6 +683,9 @@ iwn_attach(device_t dev)
TASK_INIT(&sc->sc_radioon_task, 0, iwn_radio_on, sc);
TASK_INIT(&sc->sc_radiooff_task, 0, iwn_radio_off, sc);
TASK_INIT(&sc->sc_panic_task, 0, iwn_panicked, sc);
TASK_INIT(&sc->sc_xmit_task, 0, iwn_xmit_task, sc);
mbufq_init(&sc->sc_xmit_queue, 1024);
sc->sc_tq = taskqueue_create("iwn_taskq", M_WAITOK,
taskqueue_thread_enqueue, &sc->sc_tq);
@ -1360,6 +1364,28 @@ iwn_vap_delete(struct ieee80211vap *vap)
free(ivp, M_80211_VAP);
}
static void
iwn_xmit_queue_drain(struct iwn_softc *sc)
{
struct mbuf *m;
struct ieee80211_node *ni;
IWN_LOCK_ASSERT(sc);
while ((m = mbufq_dequeue(&sc->sc_xmit_queue)) != NULL) {
ni = (struct ieee80211_node *)m->m_pkthdr.rcvif;
ieee80211_free_node(ni);
m_freem(m);
}
}
static int
iwn_xmit_queue_enqueue(struct iwn_softc *sc, struct mbuf *m)
{
IWN_LOCK_ASSERT(sc);
return (mbufq_enqueue(&sc->sc_xmit_queue, m));
}
static int
iwn_detach(device_t dev)
{
@ -1373,6 +1399,11 @@ iwn_detach(device_t dev)
if (ifp != NULL) {
ic = ifp->if_l2com;
/* Free the mbuf queue and node references */
IWN_LOCK(sc);
iwn_xmit_queue_drain(sc);
IWN_UNLOCK(sc);
ieee80211_draintask(ic, &sc->sc_reinit_task);
ieee80211_draintask(ic, &sc->sc_radioon_task);
ieee80211_draintask(ic, &sc->sc_radiooff_task);
@ -2831,6 +2862,9 @@ iwn_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
sc->rxon->filter &= ~htole32(IWN_FILTER_BSS);
sc->calib.state = IWN_CALIB_STATE_INIT;
/* Wait until we hear a beacon before we transmit */
sc->sc_beacon_wait = 1;
if ((error = iwn_auth(sc, vap)) != 0) {
device_printf(sc->sc_dev,
"%s: could not move to auth state\n", __func__);
@ -2846,6 +2880,9 @@ iwn_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
break;
}
/* Wait until we hear a beacon before we transmit */
sc->sc_beacon_wait = 1;
/*
* !RUN -> RUN requires setting the association id
* which is done with a firmware cmd. We also defer
@ -2859,6 +2896,12 @@ iwn_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
case IEEE80211_S_INIT:
sc->calib.state = IWN_CALIB_STATE_INIT;
/*
* Purge the xmit queue so we don't have old frames
* during a new association attempt.
*/
sc->sc_beacon_wait = 0;
iwn_xmit_queue_drain(sc);
break;
default:
@ -3066,6 +3109,32 @@ iwn_rx_done(struct iwn_softc *sc, struct iwn_rx_desc *desc,
}
}
/*
* If it's a beacon and we're waiting, then do the
* wakeup. This should unblock raw_xmit/start.
*/
if (sc->sc_beacon_wait) {
uint8_t type, subtype;
/* NB: Re-assign wh */
wh = mtod(m, struct ieee80211_frame *);
type = wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK;
subtype = wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK;
/*
* This assumes at this point we've received our own
* beacon.
*/
DPRINTF(sc, IWN_DEBUG_TRACE,
"%s: beacon_wait, type=%d, subtype=%d\n",
__func__, type, subtype);
if (type == IEEE80211_FC0_TYPE_MGT &&
subtype == IEEE80211_FC0_SUBTYPE_BEACON) {
DPRINTF(sc, IWN_DEBUG_TRACE | IWN_DEBUG_XMIT,
"%s: waking things up\n", __func__);
/* queue taskqueue to transmit! */
taskqueue_enqueue(sc->sc_tq, &sc->sc_xmit_task);
}
}
IWN_UNLOCK(sc);
/* Send the frame to the 802.11 layer. */
@ -4802,6 +4871,51 @@ iwn_tx_data_raw(struct iwn_softc *sc, struct mbuf *m,
return 0;
}
static void
iwn_xmit_task(void *arg0, int pending)
{
struct iwn_softc *sc = arg0;
struct ifnet *ifp = sc->sc_ifp;
struct ieee80211_node *ni;
struct mbuf *m;
int error;
struct ieee80211_bpf_params p;
int have_p;
DPRINTF(sc, IWN_DEBUG_XMIT, "%s: called\n", __func__);
IWN_LOCK(sc);
/*
* Dequeue frames, attempt to transmit,
* then disable beaconwait when we're done.
*/
while ((m = mbufq_dequeue(&sc->sc_xmit_queue)) != NULL) {
have_p = 0;
ni = (struct ieee80211_node *)m->m_pkthdr.rcvif;
/* Get xmit params if appropriate */
if (ieee80211_get_xmit_params(m, &p) == 0)
have_p = 1;
DPRINTF(sc, IWN_DEBUG_XMIT, "%s: m=%p, have_p=%d\n",
__func__, m, have_p);
/* If we have xmit params, use them */
if (have_p)
error = iwn_tx_data_raw(sc, m, ni, &p);
else
error = iwn_tx_data(sc, m, ni);
if (error != 0) {
ieee80211_free_node(ni);
if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
}
}
sc->sc_beacon_wait = 0;
IWN_UNLOCK(sc);
}
static int
iwn_raw_xmit(struct ieee80211_node *ni, struct mbuf *m,
const struct ieee80211_bpf_params *params)
@ -4819,7 +4933,25 @@ iwn_raw_xmit(struct ieee80211_node *ni, struct mbuf *m,
return ENETDOWN;
}
/* XXX? net80211 doesn't set this on xmit'ed raw frames? */
m->m_pkthdr.rcvif = (void *) ni;
IWN_LOCK(sc);
/* queue frame if we have to */
if (sc->sc_beacon_wait) {
if (iwn_xmit_queue_enqueue(sc, m) != 0) {
m_freem(m);
ieee80211_free_node(ni);
if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
IWN_UNLOCK(sc);
return (ENOBUFS);
}
/* Queued, so just return OK */
IWN_UNLOCK(sc);
return (0);
}
if (params == NULL) {
/*
* Legacy path; interpret frame contents to decide
@ -4866,6 +4998,14 @@ iwn_start_locked(struct ifnet *ifp)
IWN_LOCK_ASSERT(sc);
/*
* If we're waiting for a beacon, we can just exit out here
* and wait for the taskqueue to be kicked.
*/
if (sc->sc_beacon_wait) {
return;
}
DPRINTF(sc, IWN_DEBUG_XMIT, "%s: called\n", __func__);
if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||

11
sys/dev/iwn/if_iwnvar.h
View File

@ -309,6 +309,7 @@ struct iwn_softc {
struct task sc_radioon_task;
struct task sc_radiooff_task;
struct task sc_panic_task;
struct task sc_xmit_task;
/* Taskqueue */
struct taskqueue *sc_tq;
@ -385,6 +386,9 @@ struct iwn_softc {
/* Are we doing a scan? */
int sc_is_scanning;
/* Are we waiting for a beacon before xmit? */
int sc_beacon_wait;
struct ieee80211_tx_ampdu *qid2tap[IWN5000_NTXQUEUES];
int (*sc_ampdu_rx_start)(struct ieee80211_node *,
@ -417,6 +421,13 @@ struct iwn_softc {
#define IWN_UCODE_API(ver) (((ver) & 0x0000FF00) >> 8)
uint32_t ucode_rev;
/*
* Global queue for queuing xmit frames
* when we can't yet transmit (eg raw
* frames whilst waiting for beacons.)
*/
struct mbufq sc_xmit_queue;
};
#define IWN_LOCK_INIT(_sc) \