# kernel 3.3.8-gentoo / SW-IOMMU messages

## little_bob

hi community,

i have a box with

- gentoo kernel 3.3.8

- usb wlan stick TP-Link TL-WN821N v3 802.11n [Atheros AR7010+AR9287]

- asrock Z77E-ITX

i am using this box as a wlan access point.

it is running since a few days. now i have the following entry in my messages file which comes a few times every second

```

Dec 12 06:17:32 bespin kernel: [299112.882203] DMA: Out of SW-IOMMU space for 16 bytes at device 0000:00:1d.0

```

lspci show that device 1d.0 is the usb controller

```

00:1d.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset Family USB Enhanced Host Controller #1 (rev 04)

```

so i guess this comes from the usb wlan stick. also since this kernel message i am not able to establish a wlan connection with a client.

i am using this config - hostapd

```

interface=wlan3

bridge=br0

driver=nl80211

logger_syslog=-1

logger_syslog_level=2

logger_stdout=-1

logger_stdout_level=2

dump_file=/tmp/hostapd.dump

ctrl_interface=/var/run/hostapd

ctrl_interface_group=0

ssid=hutzi2013!

#macaddr_acl=0

auth_algs=3

eap_server=0

eapol_key_index_workaround=0

own_ip_addr=127.0.0.1

wpa=3

ieee8021x=0

wpa_passphrase=**********

wpa_key_mgmt=WPA-PSK

wpa_pairwise=CCMP TKIP

hw_mode=g

channel=8

wme_enabled=1

ieee80211n=1

```

do i have a missmatch in my config from hostapd or in my kernel?

best regards

--christian

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## little_bob

additional info.

when the error come up i was using vlc to watch a video. the video file was mounted via nfs.

----------

## _______0

I have the exact same hardware and had the same issue which was resolved by updating to 3.7.0.

best regards.

----------

## _______0

I have the exact same hardware and had the same issue which was resolved by updating to 3.7.0.

best regards.

----------

