On Friday 12 July 2013 15:47:40 Piotr Haber wrote:
> On 07/12/13 14:55, Maximilian Engelhardt wrote:
> > On Friday 21 June 2013 20:26:25 Maximilian Engelhardt wrote:
> >> Hello developers,
> >>
> >> I'm having problems with the reception performance of my BCM4313 wireless
> >> card. The card is basically working fine, but the reception is quite bad
> >> compared to other wifi equipment. I first suspected a hardware problem,
> >> but
> >> after I tried Windows 7 with the same hardware and having no problem
> >> there
> >> I'm quite sure this is a software issue.
> >>
> >>
> >> Here is a more detailed explanation of a test setup I performed to show
> >> the
> >> problem:
> >>
> >> I have an AP in about 2m distance and I connected to it by my BCM4313
> >> card
> >> and by a USB dongle (TP-Link TL-WN821N, using ath9k_htc). Both
> >> connections
> >> work and I can ping the AP using both cards.
> >>
> >> iw dev $DEV link shows a signal of about -68 dBm for the broadcom card
> >> and
> >> about -51 dBm for the atheros dongle. I have no idea in how far one can
> >> trust these values, but the difference between these two cards mostly
> >> seems
> >> to be 20-30 dB, also in my further experiments (greater distance from the
> >> AP).
> >>
> >> Now with both dongles being connected I move my laptop away from the AP
> >> and
> >> of course the signal is getting weaker. However at some point the
> >> broadcom
> >> card looses the connection to the AP while the USB dongle still has good
> >> connection (at this point the signal strength of the broadcom card is
> >> about
> >> -90dBm and -60dBm for the USB dongle). In my test with the Windows driver
> >> at that point the connection was still good and maximum distance till I
> >> lost the connection was much larger. So I don't think is a hardware
> >> problem.
> >>
> >> In general I can say my BCM4313 card is only usable when I'm in vicinity
> >> of
> >> the AP. If I move further away the connection becomes unusable slow or is
> >> lost, while it is still working well using other cards/drivers.
> >>
> >>
> >> I'm currently using a 3.10-rc5 kernel with Debian jessie (kernel is from
> >> experimental, but the same behavior has been there with kernel 3.9, 3.8
> >> (and older)). The driver used for the broadcom card is brcmsmac.
> >>
> >>
> >> I did a search non the Internet regarding this issue and found some other
> >> people having the same problem but no real solution to this. There is a
> >> workaround some Ubuntu related sites, which consists of blacklisting the
> >> brcmsmac driver and installing the wl driver. With the wl driver this
> >> problem seems to be fixed according to the web (I didn't try it myself).
> >>
> >> As I have no idea where this problem could be and how I can debug it, so
> >> I'm writing this mail now. If you need any addition information I'm
> >> happy to provide it.
> >> From the numbers shown above it seems like there is an attenuator of
> >> 20-30dB active on the receiver of the broadcom card.
> >
> > [...]
> >
> >
> > Hello,
> >
> > Is there any progress on this issue?
> > Here are the results of some additional test I performed.
> >
> >
> > I set up a AP (11g) and connected two client to it. The clients were my
> > bcm4313 wireless card and the TP-Link TL-WN821N USB dongle which was
> > connected to the laptop with the broadcom card. I connected both cards to
> > the AP. The distance between the cards and the AP was about 3m.
> > Then I set up another wireless card (TP-WN722N) in monitor mode about 3m
> > away from the AP and about 3m away from the laptop with the two wireless
> > cards. This card was connected to a different PC and I captured the data
> > of the clients and the AP. I then had a look at the reported SSI. You can
> > see my measured results below:
> >
> > SSI for packets from the AP: -27 to -23dBm
> > SSI for packets from client1 (broadcom): -20 to -14dBm
> > SSI for packets from client2 (atheros): -40 to -38dBm
> >
> > The received signal from the broadcom card were quite strong. The signal
> > from the AP was a bit weaker. Interestingly the signal from the second
> > card was noticeably weaker. I didn't investigate any further as I wanted
> > to know how the broadcom cards performs in transmitting. So for me
> > transmitting power seems to be fine with the broadcom card. My guess for
> > the weaker signal from the 2nd client is ether some active power saving
> > or different propagation conditions.
> >
> > Here are the reported signal strength from the clients (while being
> > connected to the AP):
> > client1 (broadcom): -74 to -75dBm
> > client2 (atheros): -44 to -42dBm
> >
> >
> > So for me this test shows that the card only seems to have problems on
> > receiving packets, transmitting seems to work fine.
> >
> >
> >
> > Additionally I performed a test with the wl driver. I booted an ubuntu
> > live CD and installed the wl driver there. Then I connected to my AP
> > using this driver and tested reception. Everything looked like it was
> > supposed to work. After connecting to the AP I got a reported signal
> > strength of about -38dBm. I then moved away from the AP and was still
> > able to get good connection where before I wasn't able to get any
> > connection at all using the brcmsmac driver.
> >
> >
> >
> > Please let me know if I should perform any additional tests or if you need
> > any additional information.
> >
> >
> > Greetings,
> > Maxi
>
> Hi Maximilian,
>
> poor rx performance is observed on Wifi/Bluetooth combo modules (which
> according to hardware info sent before you have), I'm working on this
> problem.
>
> Is Bluetooth function of the card usable under linux? What about windows?
> Could you send me output of 'lspci -nn'?
>
> Kind regards
> Piotr
Hi Piotr,
Thank you for you reply, it's nice to hear you are working on this.
I don't use any other Bluetooth devices, however I did some tests in the past
and there I was able to find other devices and connect to them, so I think
Bluetooth should be working. I can do some better testing if you think it
might be useful.
However I'm not 100% sure that my wifi card is also used for Bluetooth. I have
the following usb device which seems to be a Blutooth device (see below for
more details):
$ lsusb -s 004:004
Bus 004 Device 004: ID 0a5c:21f4 Broadcom Corp.
I did a test with Windows some time ago and there wifi did work fine. However
I did not test Bluetooth on Windows. As testing with Windows is quite
complicated for me, so I want to avoid it if possible.
You can find the output of 'lspci -nn' below.
$ lsusb
Bus 004 Device 004: ID 0a5c:21f4 Broadcom Corp.
Bus 007 Device 003: ID 5986:0299 Acer, Inc
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 006 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 007 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
$ lsusb -t
/: Bus 07.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/5p, 480M
|__ Port 4: Dev 3, If 0, Class=Video, Driver=uvcvideo, 480M
|__ Port 4: Dev 3, If 1, Class=Video, Driver=uvcvideo, 480M
/: Bus 06.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/5p, 480M
/: Bus 05.Port 1: Dev 1, Class=root_hub, Driver=ohci_hcd/2p, 12M
/: Bus 04.Port 1: Dev 1, Class=root_hub, Driver=ohci_hcd/5p, 12M
|__ Port 3: Dev 4, If 0, Class=Vendor Specific Class, Driver=btusb, 12M
|__ Port 3: Dev 4, If 1, Class=Vendor Specific Class, Driver=btusb, 12M
|__ Port 3: Dev 4, If 2, Class=Vendor Specific Class, Driver=, 12M
|__ Port 3: Dev 4, If 3, Class=Application Specific Interface, Driver=, 12M
/: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=ohci_hcd/5p, 12M
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/2p, 5000M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/2p, 480M
$ lsusb -v -s 004:004
Bus 004 Device 004: ID 0a5c:21f4 Broadcom Corp.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 255 Vendor Specific Class
bDeviceSubClass 1
bDeviceProtocol 1
bMaxPacketSize0 64
idVendor 0x0a5c Broadcom Corp.
idProduct 0x21f4
bcdDevice 1.12
iManufacturer 1 Broadcom Corp
iProduct 2 BCM20702A0
iSerial 3 C0143DC1809E
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 218
bNumInterfaces 4
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xe0
Self Powered
Remote Wakeup
MaxPower 0mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 3
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 1
bInterfaceProtocol 1
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0010 1x 16 bytes
bInterval 1
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 1
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 1
bInterfaceProtocol 1
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 1
Transfer Type Isochronous
Synch Type None
Usage Type Data
wMaxPacketSize 0x0000 1x 0 bytes
bInterval 1
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x03 EP 3 OUT
bmAttributes 1
Transfer Type Isochronous
Synch Type None
Usage Type Data
wMaxPacketSize 0x0000 1x 0 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 1
bNumEndpoints 2
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 1
bInterfaceProtocol 1
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 1
Transfer Type Isochronous
Synch Type None
Usage Type Data
wMaxPacketSize 0x0009 1x 9 bytes
bInterval 1
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x03 EP 3 OUT
bmAttributes 1
Transfer Type Isochronous
Synch Type None
Usage Type Data
wMaxPacketSize 0x0009 1x 9 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 2
bNumEndpoints 2
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 1
bInterfaceProtocol 1
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 1
Transfer Type Isochronous
Synch Type None
Usage Type Data
wMaxPacketSize 0x0011 1x 17 bytes
bInterval 1
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x03 EP 3 OUT
bmAttributes 1
Transfer Type Isochronous
Synch Type None
Usage Type Data
wMaxPacketSize 0x0011 1x 17 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 3
bNumEndpoints 2
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 1
bInterfaceProtocol 1
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 1
Transfer Type Isochronous
Synch Type None
Usage Type Data
wMaxPacketSize 0x0019 1x 25 bytes
bInterval 1
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x03 EP 3 OUT
bmAttributes 1
Transfer Type Isochronous
Synch Type None
Usage Type Data
wMaxPacketSize 0x0019 1x 25 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 4
bNumEndpoints 2
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 1
bInterfaceProtocol 1
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 1
Transfer Type Isochronous
Synch Type None
Usage Type Data
wMaxPacketSize 0x0021 1x 33 bytes
bInterval 1
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x03 EP 3 OUT
bmAttributes 1
Transfer Type Isochronous
Synch Type None
Usage Type Data
wMaxPacketSize 0x0021 1x 33 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 5
bNumEndpoints 2
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 1
bInterfaceProtocol 1
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 1
Transfer Type Isochronous
Synch Type None
Usage Type Data
wMaxPacketSize 0x0031 1x 49 bytes
bInterval 1
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x03 EP 3 OUT
bmAttributes 1
Transfer Type Isochronous
Synch Type None
Usage Type Data
wMaxPacketSize 0x0031 1x 49 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 2
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 255 Vendor Specific Subclass
bInterfaceProtocol 255 Vendor Specific Protocol
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x84 EP 4 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0020 1x 32 bytes
bInterval 1
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x04 EP 4 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0020 1x 32 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 3
bAlternateSetting 0
bNumEndpoints 0
bInterfaceClass 254 Application Specific Interface
bInterfaceSubClass 1 Device Firmware Update
bInterfaceProtocol 1
iInterface 0
Device Firmware Upgrade Interface Descriptor:
bLength 9
bDescriptorType 33
bmAttributes 5
Will Not Detach
Manifestation Tolerant
Upload Unsupported
Download Supported
wDetachTimeout 5000 milliseconds
wTransferSize 64 bytes
bcdDFUVersion 1.10
Device Status: 0x0001
Self Powered
$ lspci -nn
00:00.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Family 14h Processor Root Complex [1022:1510]
00:01.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Wrestler [Radeon HD 7340] [1002:9808]
00:01.1 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI] Wrestler HDMI Audio [1002:1314]
00:05.0 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Family 14h Processor Root Port [1022:1513]
00:06.0 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Family 14h Processor Root Port [1022:1514]
00:07.0 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Family 14h Processor Root Port [1022:1515]
00:10.0 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD] FCH USB XHCI Controller [1022:7812] (rev 03)
00:11.0 SATA controller [0106]: Advanced Micro Devices, Inc. [AMD] FCH SATA Controller [AHCI mode] [1022:7801]
00:12.0 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD] FCH USB OHCI Controller [1022:7807] (rev 11)
00:12.2 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD] FCH USB EHCI Controller [1022:7808] (rev 11)
00:13.0 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD] FCH USB OHCI Controller [1022:7807] (rev 11)
00:13.2 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD] FCH USB EHCI Controller [1022:7808] (rev 11)
00:14.0 SMBus [0c05]: Advanced Micro Devices, Inc. [AMD] FCH SMBus Controller [1022:780b] (rev 14)
00:14.2 Audio device [0403]: Advanced Micro Devices, Inc. [AMD] FCH Azalia Controller [1022:780d] (rev 01)
00:14.3 ISA bridge [0601]: Advanced Micro Devices, Inc. [AMD] FCH LPC Bridge [1022:780e] (rev 11)
00:14.4 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] FCH PCI Bridge [1022:780f] (rev 40)
00:14.5 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD] FCH USB OHCI Controller [1022:7809] (rev 11)
00:18.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 0 [1022:1700] (rev 43)
00:18.1 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 1 [1022:1701]
00:18.2 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 2 [1022:1702]
00:18.3 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 3 [1022:1703]
00:18.4 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 4 [1022:1704]
00:18.5 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 6 [1022:1718]
00:18.6 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 5 [1022:1716]
00:18.7 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 7 [1022:1719]
02:00.0 Network controller [0280]: Broadcom Corporation BCM4313 802.11b/g/n Wireless LAN Controller [14e4:4727] (rev 01)
03:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [10ec:8168] (rev 07)
04:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS5209 PCI Express Card Reader [10ec:5209] (rev 01)
Greetings and thanks for your help,
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