Hello,
I recently got a Intel Dual Band Wireless-AC 7260 card, which works very
well as a 802.11 wlan module. So I am now trying to break the Bluetooth
part of it instead :)
And I do find some issues with that... The most important one is that I
cannot get it to work properly with autosuspend enabled.
I currently have two btusb devices in my laptop, the Intel device and an
older Lenovo Broadcom-based device. Autosuspend is enabled for all
USB devices.
nemi:/tmp# hciconfig
hci1: Type: BR/EDR Bus: USB
BD Address: 0C:8B:FD:08:09:75 ACL MTU: 1021:5 SCO MTU: 96:5
UP RUNNING PSCAN
RX bytes:965 acl:0 sco:0 events:48 errors:0
TX bytes:963 acl:0 sco:0 commands:48 errors:0
hci0: Type: BR/EDR Bus: USB
BD Address: 00:23:4D:F0:D9:1A ACL MTU: 1021:8 SCO MTU: 64:1
UP RUNNING PSCAN ISCAN
RX bytes:885 acl:0 sco:0 events:38 errors:0
TX bytes:894 acl:0 sco:0 commands:38 errors:0
The Lenovo device works as expected, with autosuspend. Reading the
version info as a simple HCI test:
nemi:/tmp# hciconfig hci0 version
hci0: Type: BR/EDR Bus: USB
BD Address: 00:23:4D:F0:D9:1A ACL MTU: 1021:8 SCO MTU: 64:1
HCI Version: 2.1 (0x4) Revision: 0x518f
LMP Version: 2.1 (0x4) Subversion: 0x424c
Manufacturer: Broadcom Corporation (15)
But the Intel device fails if suspended (and will fail for any HCI
command):
nemi:/tmp# hciconfig hci1 version
Can't read version info hci1: Connection timed out (110)
The driver is of course the same, and the configuration of these devices
are similar:
nemi:/tmp# ls -l /sys/class/bluetooth/
total 0
lrwxrwxrwx 1 root root 0 Jul 3 13:44 hci0 -> ../../devices/pci0000:00/0000:00:1a.1/usb4/4-2/4-2:1.0/bluetooth/hci0
lrwxrwxrwx 1 root root 0 Jul 3 13:44 hci1 -> ../../devices/pci0000:00/0000:00:1d.1/usb7/7-1/7-1:1.0/bluetooth/hci1
nemi:/tmp# grep . /sys/class/bluetooth/hci*/device/supports_autosuspend
/sys/class/bluetooth/hci0/device/supports_autosuspend:1
/sys/class/bluetooth/hci1/device/supports_autosuspend:1
nemi:/tmp# grep . /sys/class/bluetooth/hci*/device/../power/control
/sys/class/bluetooth/hci0/device/../power/control:auto
/sys/class/bluetooth/hci1/device/../power/control:auto
nemi:/tmp# grep . /sys/class/bluetooth/hci*/device/../power/runtime_*
/sys/class/bluetooth/hci0/device/../power/runtime_active_kids:0
/sys/class/bluetooth/hci0/device/../power/runtime_active_time:48448
/sys/class/bluetooth/hci0/device/../power/runtime_enabled:enabled
/sys/class/bluetooth/hci0/device/../power/runtime_status:suspended
/sys/class/bluetooth/hci0/device/../power/runtime_suspended_time:1502332
/sys/class/bluetooth/hci0/device/../power/runtime_usage:0
/sys/class/bluetooth/hci1/device/../power/runtime_active_kids:0
/sys/class/bluetooth/hci1/device/../power/runtime_active_time:79528
/sys/class/bluetooth/hci1/device/../power/runtime_enabled:enabled
/sys/class/bluetooth/hci1/device/../power/runtime_status:suspended
/sys/class/bluetooth/hci1/device/../power/runtime_suspended_time:1470828
/sys/class/bluetooth/hci1/device/../power/runtime_usage:0
Turning off autosuspend for the Intel device makes it work:
nemi:/tmp# echo on > /sys/class/bluetooth/hci1/device/../power/control
nemi:/tmp# hciconfig hci1 version
hci1: Type: BR/EDR Bus: USB
BD Address: 0C:8B:FD:08:09:75 ACL MTU: 1021:5 SCO MTU: 96:5
HCI Version: 4.0 (0x6) Revision: 0x500
LMP Version: 4.0 (0x6) Subversion: 0x500
Manufacturer: Intel Corp. (2)
But this just does not seem right? Any modern USB device is supposed to
support autosuspend, right? I am using the firmware patch included in
the latest public firmware repo:
[ 4.652631] Bluetooth: hci1: read Intel version: 370710018002030d00
[ 4.656988] Bluetooth: hci1: Intel Bluetooth firmware file: intel/ibt-hw-37.7.10-fw-1.80.2.3.d.bseq
[ 4.963497] Bluetooth: hci1: Intel Bluetooth firmware patch completed and activated
While looking at this, I also noticed a minor issue with the USB
descriptors. It cannot be classified as a bug, but it does look like
somebody just forgot to set the iManufacturer, iProduct and iSerial
string indexes in the device descriptor:
Bus 007 Device 002: ID 8087:07dc Intel Corp.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 224 Wireless
bDeviceSubClass 1 Radio Frequency
bDeviceProtocol 1 Bluetooth
bMaxPacketSize0 64
idVendor 0x8087 Intel Corp.
idProduct 0x07dc
bcdDevice 0.01
iManufacturer 0
iProduct 0
iSerial 0
bNumConfigurations 1
[..]
because trying to pull some string descriptors from the device revealed
that indexes 1, 2 and 3 exist without being referenced anywhere:
1: Intel(R) Corporation
2: Intel(R) Wilkins Peak 2x2
3: 001122334455 WP_A0
The serial number doesn't look right, but the two others should fit
nicely as iManufacturer and iProduct.
Bjørn
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