Re: Troubleshooting mwl8k driver issue

[Lennert Buytenhek <buytenh@wantstofly.org>]

On Fri, Jun 03, 2016 at 10:54:52PM -0500, David Gilman wrote:

> Lennert, I am a user of your mwl8k driver through the OpenWRT
> distribution.  When working with certain WiFi devices I get errors in
> the kernel logs and network connectivity errors on the wireless device.
> The dmesg logs look like this:
> 
> [539374.394607] ieee80211 phy1: Added a new stream for (BSSID MAC) 0
> [539374.394650] ieee80211 phy1: Started stream for (BSSID MAC) 0
> [539374.394732] ieee80211 phy1: tx rings drained
> [539374.401372] ieee80211 phy1: Created a BA stream for (BSSID MAC) : tid 0

These are not (necessarily) errors, just debug messages


> There are a number of other users who are also experiencing the same
> issue on the OpenWRT bug tracker:
> 
> https://dev.openwrt.org/ticket/21284

There's a bunch of bad-looking stuff in the posted dmesgs, such as:

[ 10.983657] pci 0000:00:01.0: enabling device (0140 -> 0142)
[ 11.972069] ieee80211 phy0: Command RF_ANTENNA error 0x2
[ 11.977455] ieee80211 phy0: failed to set # of RX antennas
[ 11.993318] ieee80211 phy0: Command RF_ANTENNA error 0x2
[ 11.998713] ieee80211 phy0: failed to set # of TX antennas
[ 12.004243] ieee80211 phy0: 88w8366 v48, c8d719177244, STA firmware 4.1.0.3

And:

[ 22.517451] 0000:02:00.0: unable to load firmware helper image
[ 22.523399] ieee80211 phy1: Cannot start firmware
[ 22.528230] ieee80211 phy1: Trying to reload the firmware again
[ 23.016669] ieee80211 phy1: 88w8366 v7, c8d719177246, AP firmware 5.2.8.17


> As I noted in the bug the driver works with some of my wireless devices
> and not others which suggests that something subtle is up with some
> driver in this picture.

Is the behavior consistent per device across boots?  I.e. does device
X always work on every boot while device Y never works at all?


> I don't have a whole lot of experience with kernel development (pretty
> much none actually) and I know absolutely nothing about how these WiFi
> devices work.  However I am willing to work with you or anyone else on
> the linux-wireless list (which I have CCd) to help troubleshoot this
> issue.  I am using OpenWRT on this router and I can get a build
> environment set up for debug kernel builds with their toolchain.  I'm
> running a pretty recent kernel (4.4.7) but git log suggests this driver
> hasn't been touched in a while.

For starters, could you post lspci -n output?

Also, do you see the same behavior with older kernels, or have you
only tried 4.4?