diff options
| author | Stefan Sperling <stsp@cvs.openbsd.org> | 2017-12-20 18:21:00 +0000 |
|---|---|---|
| committer | Stefan Sperling <stsp@cvs.openbsd.org> | 2017-12-20 18:21:00 +0000 |
| commit | db0035fdafcb624368c6443fc8f0edca087beed0 (patch) | |
| tree | 63424b542b5b23dfce66f6d935f66b1f79d1fb71 /sys/dev | |
| parent | b0af161c7b32253d9c8bf4ea7e05b95dd5e8510b (diff) | |
Two background scan fixes for iwn(4) (4965 devices only):
1) Use only one antenna while scanning on 5GHz. Fixes very low RSSI values.
2) During a background scan while associated to a 5GHz AP, send probe
requests on 2GHz channels with an OFDM rate (6Mbps) because the buggy
firmware does not like sending with a CCK rate (1Mbps) in this state.
CCK rates are not valid for 5GHz, which could explain this firmware bug.
Taken from FreeBSD r222679.
jca@ tested and confirmed the first problem but lacks a 5GHz access point to
associate to and test the second one with.
I am going to *blindly trust* FreeBSD on the second one! It is not a big deal
if it doesn't actually apply to our firmware version as the change itself is
rather inconsequential in practice. And 4965 hardware is quite rare nowadays.
ok jca@
Diffstat (limited to 'sys/dev')
| -rw-r--r-- | sys/dev/pci/if_iwn.c | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/sys/dev/pci/if_iwn.c b/sys/dev/pci/if_iwn.c index 2c8c1226aaa..ff68fb266b0 100644 --- a/sys/dev/pci/if_iwn.c +++ b/sys/dev/pci/if_iwn.c @@ -1,4 +1,4 @@ -/* $OpenBSD: if_iwn.c,v 1.196 2017/12/14 20:12:32 stsp Exp $ */ +/* $OpenBSD: if_iwn.c,v 1.197 2017/12/20 18:20:59 stsp Exp $ */ /*- * Copyright (c) 2007-2010 Damien Bergamini <damien.bergamini@free.fr> @@ -4741,8 +4741,11 @@ iwn_scan(struct iwn_softc *sc, uint16_t flags, int bgscan) IWN_RXCHAIN_DRIVER_FORCE; if ((flags & IEEE80211_CHAN_5GHZ) && sc->hw_type == IWN_HW_REV_TYPE_4965) { - /* Ant A must be avoided in 5GHz because of an HW bug. */ - rxchain |= IWN_RXCHAIN_FORCE_SEL(IWN_ANT_BC); + /* + * On 4965 ant A and C must be avoided in 5GHz because of a + * HW bug which causes very weak RSSI values being reported. + */ + rxchain |= IWN_RXCHAIN_FORCE_SEL(IWN_ANT_B); } else /* Use all available RX antennas. */ rxchain |= IWN_RXCHAIN_FORCE_SEL(sc->rxchainmask); hdr->rxchain = htole16(rxchain); @@ -4759,9 +4762,19 @@ iwn_scan(struct iwn_softc *sc, uint16_t flags, int bgscan) rs = &ic->ic_sup_rates[IEEE80211_MODE_11A]; } else { hdr->flags = htole32(IWN_RXON_24GHZ | IWN_RXON_AUTO); - /* Send probe requests at 1Mbps. */ - tx->plcp = iwn_rates[IWN_RIDX_CCK1].plcp; - tx->rflags = IWN_RFLAG_CCK; + if (bgscan && sc->hw_type == IWN_HW_REV_TYPE_4965 && + sc->rxon.chan > 14) { + /* + * 4965 firmware can crash when sending probe requests + * with CCK rates while associated to a 5GHz AP. + * Send probe requests at 6Mbps OFDM as a workaround. + */ + tx->plcp = iwn_rates[IWN_RIDX_OFDM6].plcp; + } else { + /* Send probe requests at 1Mbps. */ + tx->plcp = iwn_rates[IWN_RIDX_CCK1].plcp; + tx->rflags = IWN_RFLAG_CCK; + } rs = &ic->ic_sup_rates[IEEE80211_MODE_11G]; } /* Use the first valid TX antenna. */ |