by Larry Finger

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Subject: Re: rtl8192ce:rtl92ce_get_hw_reg():<0-0> switch case not processed

On 09/22/2016 04:51 AM, Jean Delvare wrote:
> Hello,
>
> I bought an Asus PCE-N10 PCIe Wi-Fi N card to install in my wife's
> computer. This morning it stopped working suddenly. Investigating the
> kernel logs, the following error message caught my eye:
>
> rtl8192ce:rtl92ce_get_hw_reg():<0-0> switch case not processed
>
> It was printed twice, 3.5 hours apart, the second time at the moment
> the network stopped working. I guess this is not supposed to happen.
> What additional information can I provide to help you debug the issue?
> That's the device:
>
> 03:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. RTL8188CE 802.11b/g/n WiFi Adapter [10ec:8176] (rev 01)
> Subsystem: ASUSTeK Computer Inc. Device [1043:84b5]
> Flags: bus master, fast devsel, latency 0, IRQ 17
> I/O ports at e800 [size=256]
> Memory at febfc000 (64-bit, non-prefetchable) [size=16K]
> Capabilities: <access denied>
> Kernel driver in use: rtl8192ce
> Kernel modules: rtl8192ce
>
> Kernel version is 4.5.4-1-default x86_64 (openSUSE Tumbleweed.)
>
> Reloading the rtl8192ce module and restarting the network service got
> everything back up.

Unfortunately, that message is not as helpful as it might be.

Do you build your own kernel, or are you using openSUSE's supplied version? If
the latter, I will need to think how we might debug the issue. If the former,
please add the attached patch.

Larry

Attachments:

rtl8192ce_debug.diff (518.00 B)

2016-09-23 19:07:40

by Larry Finger

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Subject: Re: [PATCH] realtek: Add switch variable to 'switch case not processed' messages

2016-09-23 18:10:30

by Larry Finger

[permalink] [raw]

Subject: Re: rtl8192ce:rtl92ce_get_hw_reg():<0-0> switch case not processed

On 09/23/2016 07:16 AM, Jean Delvare wrote:
> Hi Larry,
>
> On Thu, 22 Sep 2016 10:09:58 -0500, Larry Finger wrote:
>> Do you build your own kernel, or are you using openSUSE's supplied version? If
>> the latter, I will need to think how we might debug the issue. If the former,
>> please add the attached patch.
>
> Lost network this morning, but no error message. We restarted the
> network service, things were back up and the error message was logged
> then:
>
> rtl8192ce:rtl92ce_get_hw_reg():<0-0> switch case 92 not processed
>
> So I think this is happening when the interface is put down, and is
> probably not related with the loss of connectivity. But it would be
> good to understand and fix it nevertheless.
>
> 92 is HAL_DEF_WOWLAN. I see it is handled differently in 2 other
> rtlwifi drivers: rtl8192cu ignores it, while rtl8821ae processes it:
>
> case HAL_DEF_WOWLAN:
> if (ppsc->wo_wlan_mode)
> *((bool *)(val)) = true;
> else
> *((bool *)(val)) = false;
> break;
>
> I don't know what is the appropriate course of action in the case of
> the rtl8192ce. Let me know if you need anything else from me.

As the RTL8192CE does not support WOWLAN, the correct response is to ignore that
call. Clearly, it has nothing to do with your network drops. One thing you might
do is add the appropriate file in /etc/modprobe.d/ so that the module is loaded
with the "ips=0" option to see if power save is messing up.

I am in the process of fixing all the instances where the log entry for the
default case does not output the switch variable. With these patches, I will
also handle the HAL_DEF_WOWLAN case.

I'm sorry about my original comments regarding patching the kernel. I sent that
E-mail before I even read your name and address. As a long-time openSUSE user, I
certainly recognize your name and your abilities.

Larry

2016-09-22 21:01:36

by Jean Delvare

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Hi Larry,

On Fri, 23 Sep 2016 13:10:28 -0500, Larry Finger wrote:
> As the RTL8192CE does not support WOWLAN, the correct response is to ignore that
> call. Clearly, it has nothing to do with your network drops. One thing you might
> do is add the appropriate file in /etc/modprobe.d/ so that the module is loaded
> with the "ips=0" option to see if power save is messing up.

OK, we have just added the option, I'll let you know if it makes a
difference.

There are other messages logged, by the way. I did not mention them
before because they don't look like errors and "switch case not
processed" was my prime suspect, but maybe they would be useful to you:

wlp3s0: AP 94:a7:b7:xx:xx:xx changed bandwidth, new config is 2427 MHz, width 2 (2437/0 MHz)
wlp3s0: AP 94:a7:b7:xx:xx:xx changed bandwidth, new config is 2427 MHz, width 1 (2427/0 MHz)
wlp3s0: AP 94:a7:b7:xx:xx:xx changed bandwidth, new config is 2427 MHz, width 2 (2437/0 MHz)

It oscillates between both values. There doesn't seem to be a
correlation with the failures. The timing doesn't appear to be fully
random, for example these are the timestamps for this morning:

[Sat. sept. 24 09:17:16 2016]
[Sat. sept. 24 09:32:11 2016]
[Sat. sept. 24 10:27:15 2016]
[Sat. sept. 24 10:52:11 2016]
[Sat. sept. 24 12:07:16 2016]
[Sat. sept. 24 12:44:22 2016]

15 minutes, 55 minutes, 25 minutes, 75 minutes... Looks like something
is checking adjusting the configuration every 5 minutes? Last one
doesn't follow the pattern though (37 minutes.)

> I am in the process of fixing all the instances where the log entry for the
> default case does not output the switch variable. With these patches, I will
> also handle the HAL_DEF_WOWLAN case.

Great, thanks.

> I'm sorry about my original comments regarding patching the kernel. I sent that
> E-mail before I even read your name and address. As a long-time openSUSE user, I
> certainly recognize your name and your abilities.

No worry :-)

--
Jean Delvare
SUSE L3 Support