mwifiex and SD8787: How to create AP interface?

mwifiex and SD8787: How to create AP interface?

[Andrew Wiley]

Hello linux-wireless,

I'm trying to get AP mode to work on a Marvell Kirkwood-based
Dreamplug with an SD8787 SDIO wireless chipset.

Originally, the mwifiex driver would create three interfaces when it
loaded - mlan0, uap0, and ptp0, for station mode, AP mode, and PTP
mode, respectively. That behavior was removed in commit 1211c (
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/net/wireless/mwifiex?id=1211c961170cedb21c30d5bb7e2033c8720b38db
) because NetworkManager was trying to use all of the interfaces
rather than just mlan0.

As I understand it, the normal workflow for this is that hostapd
changes an interface from station mode to AP mode when it starts up,
but when it tries to do this on the mlan0 interface, nl80211 returns
Operation Not Supported. Depending on the version of hostapd, it
either bails out there or tries to continue and bails out later in
setup.

If I revert the patch I linked above, the driver creates the uap0
interface and I can run an AP with hostapd (although it has some other
issues - more on that in a later post).

What is the "correct" way to access AP mode with this driver? As far
as I'm aware, there are no userspace utilities to directly create an
AP-mode interface, and mwifiex doesn't seem to support the normal
workflow that hostapd is trying to do.

Thanks,
Andrew

Fwd: mwifiex and SD8787: How to create AP interface?

[Andrew Wiley]

Hello Avinash,

Thanks! That works for me. Would it be possible to add this to the
mwifiex page on wireless.kernel.org? As far as I know, this command is
completely undocumented within iw, and I know I'm not the only
Dreamplug owner experiencing this problem.

As for other issues, I'm seeing a hang in the TX queue on the device
after running an AP for a while, but I'm still gathering information
on that. I'll follow up with another thread.

Thanks,
Andrew

On Sat, Feb 1, 2014 at 9:48 PM, Avinash Patil <avinashapatil@gmail.com> wrote:
> Hi Andrew,
>
> AP interface can be created using iw utility. Command is as follows:
>
> iw dev mlan0 interface add uap0 type __ap
>
> There onwards hostapd can be used to start mwifiex AP operations. Please let
> me know if you face any issues.
>
> Thanks,
> Avinashw
>
> On Feb 2, 2014 8:28 AM, "Andrew Wiley" <wiley.andrew.j@gmail.com> wrote:
>>
>> Hello linux-wireless,
>>
>> I'm trying to get AP mode to work on a Marvell Kirkwood-based
>> Dreamplug with an SD8787 SDIO wireless chipset.
>>
>> Originally, the mwifiex driver would create three interfaces when it
>> loaded - mlan0, uap0, and ptp0, for station mode, AP mode, and PTP
>> mode, respectively. That behavior was removed in commit 1211c (
>>
>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/net/wireless/mwifiex?id=1211c961170cedb21c30d5bb7e2033c8720b38db
>> ) because NetworkManager was trying to use all of the interfaces
>> rather than just mlan0.
>>
>> As I understand it, the normal workflow for this is that hostapd
>> changes an interface from station mode to AP mode when it starts up,
>> but when it tries to do this on the mlan0 interface, nl80211 returns
>> Operation Not Supported. Depending on the version of hostapd, it
>> either bails out there or tries to continue and bails out later in
>> setup.
>>
>> If I revert the patch I linked above, the driver creates the uap0
>> interface and I can run an AP with hostapd (although it has some other
>> issues - more on that in a later post).
>>
>> What is the "correct" way to access AP mode with this driver? As far
>> as I'm aware, there are no userspace utilities to directly create an
>> AP-mode interface, and mwifiex doesn't seem to support the normal
>> workflow that hostapd is trying to do.
>>
>> Thanks,
>> Andrew
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-wireless"
>> in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: mwifiex and SD8787: How to create AP interface?

[Avinash Patil]

Hi Andrew,

Will surely document this and other steps on mwifiex wiki page soon.

Please share timeout log as well.

Thanks,
Avinash Patil

On Sun, Feb 2, 2014 at 10:31 AM, Andrew Wiley <wiley.andrew.j@gmail.com> wrote:
> Hello Avinash,
>
> Thanks! That works for me. Would it be possible to add this to the
> mwifiex page on wireless.kernel.org? As far as I know, this command is
> completely undocumented within iw, and I know I'm not the only
> Dreamplug owner experiencing this problem.
>
> As for other issues, I'm seeing a hang in the TX queue on the device
> after running an AP for a while, but I'm still gathering information
> on that. I'll follow up with another thread.
>
> Thanks,
> Andrew
>
> On Sat, Feb 1, 2014 at 9:48 PM, Avinash Patil <avinashapatil@gmail.com> wrote:
>> Hi Andrew,
>>
>> AP interface can be created using iw utility. Command is as follows:
>>
>> iw dev mlan0 interface add uap0 type __ap
>>
>> There onwards hostapd can be used to start mwifiex AP operations. Please let
>> me know if you face any issues.
>>
>> Thanks,
>> Avinashw
>>
>> On Feb 2, 2014 8:28 AM, "Andrew Wiley" <wiley.andrew.j@gmail.com> wrote:
>>>
>>> Hello linux-wireless,
>>>
>>> I'm trying to get AP mode to work on a Marvell Kirkwood-based
>>> Dreamplug with an SD8787 SDIO wireless chipset.
>>>
>>> Originally, the mwifiex driver would create three interfaces when it
>>> loaded - mlan0, uap0, and ptp0, for station mode, AP mode, and PTP
>>> mode, respectively. That behavior was removed in commit 1211c (
>>>
>>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/net/wireless/mwifiex?id=1211c961170cedb21c30d5bb7e2033c8720b38db
>>> ) because NetworkManager was trying to use all of the interfaces
>>> rather than just mlan0.
>>>
>>> As I understand it, the normal workflow for this is that hostapd
>>> changes an interface from station mode to AP mode when it starts up,
>>> but when it tries to do this on the mlan0 interface, nl80211 returns
>>> Operation Not Supported. Depending on the version of hostapd, it
>>> either bails out there or tries to continue and bails out later in
>>> setup.
>>>
>>> If I revert the patch I linked above, the driver creates the uap0
>>> interface and I can run an AP with hostapd (although it has some other
>>> issues - more on that in a later post).
>>>
>>> What is the "correct" way to access AP mode with this driver? As far
>>> as I'm aware, there are no userspace utilities to directly create an
>>> AP-mode interface, and mwifiex doesn't seem to support the normal
>>> workflow that hostapd is trying to do.
>>>
>>> Thanks,
>>> Andrew
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe linux-wireless"
>>> in
>>> the body of a message to majordomo@vger.kernel.org
>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> --
> To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: Fwd: mwifiex and SD8787: How to create AP interface?

[James Cameron]

On Sat, Feb 01, 2014 at 11:01:02PM -0600, Andrew Wiley wrote:
> Hello Avinash,
> 
> Thanks! That works for me. Would it be possible to add this to the
> mwifiex page on wireless.kernel.org? As far as I know, this command is
> completely undocumented within iw, and I know I'm not the only
> Dreamplug owner experiencing this problem.
> 
> As for other issues, I'm seeing a hang in the TX queue on the device
> after running an AP for a while, but I'm still gathering information
> on that. I'll follow up with another thread.

I've also seen hangs, in both RX and TX, but mostly RX.

The response to failing to alloc an skb is a bit weak in mwifiex, we
noted this on OLPC XO-4 with the 8787.  You can see more about the
problem and some local fixes in our private branch:

http://dev.laptop.org/git/olpc-kernel/log/?h=arm-3.5

http://dev.laptop.org/ticket/12694 (kernel 3.5)

I did backport the latest mwifiex at the time, but it did not fix the
issue, so I dug into it more.

-- 
James Cameron
http://quozl.linux.org.au/

Re: Fwd: mwifiex and SD8787: How to create AP interface?

[Andrew Wiley]

Interesting.

I haven't seen any allocation failures in my kernel log, so I probably
have a different issue, but I'll keep an eye out.
My platform only has 512MB of RAM, so I suspect the only reason I'm
not seeing this is that I'm running an AP with no servers, so packets
are just forwarded through a layer-2 bridge rather than sent to
userspace applications.

On Sun, Feb 2, 2014 at 3:51 PM, James Cameron <quozl@laptop.org> wrote:
> On Sat, Feb 01, 2014 at 11:01:02PM -0600, Andrew Wiley wrote:
>> Hello Avinash,
>>
>> Thanks! That works for me. Would it be possible to add this to the
>> mwifiex page on wireless.kernel.org? As far as I know, this command is
>> completely undocumented within iw, and I know I'm not the only
>> Dreamplug owner experiencing this problem.
>>
>> As for other issues, I'm seeing a hang in the TX queue on the device
>> after running an AP for a while, but I'm still gathering information
>> on that. I'll follow up with another thread.
>
> I've also seen hangs, in both RX and TX, but mostly RX.
>
> The response to failing to alloc an skb is a bit weak in mwifiex, we
> noted this on OLPC XO-4 with the 8787.  You can see more about the
> problem and some local fixes in our private branch:
>
> http://dev.laptop.org/git/olpc-kernel/log/?h=arm-3.5
>
> http://dev.laptop.org/ticket/12694 (kernel 3.5)
>
> I did backport the latest mwifiex at the time, but it did not fix the
> issue, so I dug into it more.
>
> --
> James Cameron
> http://quozl.linux.org.au/