Re: RTL8192EE PCIe Wireless Network Adapter crashed with linux-4.13

[Larry Finger]

On 09/15/2017 05:10 AM, Zwindl wrote:
> > -------- Original Message --------
> > Subject: Re: RTL8192EE PCIe Wireless Network Adapter crashed with linux-4.13
> > Local Time: 14 September 2017 6:05 PM
> > UTC Time: 14 September 2017 18:05
> > From: Larry.Finger@xxxxxxxxxxxx
> > To: Zwindl <zwindl@xxxxxxxxxxxxxx>, linux-wireless@xxxxxxxxxxxxxxx 
> > <linux-wireless@xxxxxxxxxxxxxxx>
> > chaoming_li@xxxxxxxxxxxxxx <chaoming_li@xxxxxxxxxxxxxx>, kvalo@xxxxxxxxxxxxxx 
> > <kvalo@xxxxxxxxxxxxxx>, pkshih@xxxxxxxxxxx <pkshih@xxxxxxxxxxx>, 
> > johannes.berg@xxxxxxxxx <johannes.berg@xxxxxxxxx>, gregkh@xxxxxxxxxxxxxxxxxxx 
> > <gregkh@xxxxxxxxxxxxxxxxxxx>, netdev@xxxxxxxxxxxxxxx <netdev@xxxxxxxxxxxxxxx>, 
> > linux-kernel@xxxxxxxxxxxxxxx <linux-kernel@xxxxxxxxxxxxxxx>
> >
> > On 09/14/2017 08:30 AM, Zwindl wrote:
> > > Dear developers:
> > > I"m using Arch Linux with testing enabled, the current kernel version and
> > > details are
> > > `Linux zwindl 4.13.2-1-ARCH #1 SMP PREEMPT Thu Sep 14 02:57:34 UTC 2017 x86_64
> > > GNU/Linux`.
> > > The wireless card can"t work properly from the kernel 4.13. Here"s the log(in
> > > attachment) when NetworkManager trying to connect my wifi which is named as
> > > "TP", my mac addr hided as xx:xx:xx:xx:xx.
> > > What should I provide to help to debug?
> > > ZWindL.
> >
> > The BUG-ON arises in __intel_map_single() due to dir (for direction of DMA)
> > equal to DMA_NONE (3). When rtl8192ee calls pci_map_single(), it uses
> > PCI_DMA_TODEVICE (1). I followed the calling sequence through the entire chain,
> > and none of the routines made any changes to "dir", other that changing the type
> > from int to enum dma_data_direction. That would not have changed a 1 to a 3.
> >
> > I built a 4.13.2 system. The problem does not happen here. At this point, the
> > system has been up for about two hours. I did discover a small memory leak
> > associated with firmware loading, but that should not have caused the problem.
> > Nonetheless, I will be sending a patch to fix that problem.
> >
> > I will continue testing, although I doubt that the problem will happen here.
> >
> > How long had your system been up when the problem occurred? Your dmesg fragment
> > did not show any times. What kernels have you tried besides 4.13.2?
> >
> > Larry
> Oh, sorry, the original log is from `journalctl`.
> Here's the `dmesg` prints(error.txt). I can't determine which part is related, 
> so I paste all of it. I've tried 4.12.X(no issue), 4.13.1(issue), 4.13.2(issue).
> ZWindL

The output of dmesg is a lot more instructive than that of journalctl. I now 
know exactly the location that triggered the WARNING. I still do not understand 
it. In fact, it is likely a regression in kernel 4.13 that does not affect my 
Toshiba laptop, nor a Lenovo machine I have, but does affect your Lenovo laptop.

Is it possible for you to install the mainline source from vger.kernel.org using 
git and bisect the issue? It will take quite a bit of time, but it is likely the 
only way to find the offending change. If you are willing to try this, I will 
send you reasonably complete instructions.

By the way, it is usually better to load the dmesg output into a pastebin site 
and post the link. Sending the entire file to a list makes a lot of people 
receive a lot of data for which they have no interest.

Larry