Hello linux-wirelless (cc'ing stable since the original patch had
cc:stable as well),
I'm experiencing a CPU soft lockup while downloading when rtl8821ae is
loaded (even when downloading through other adapters) on a vanilla 4.2
kernel. The problem did not happen on vanilla 4.1. Bisecting shows the
first bad commit being "rtlwifi: Remove the clear interrupt routine
from all drivers" (1277fa2ab2f9a624a4b0177119ca13b5fd65edd0).
Reverting that commit makes the problem go away.
The system is perfectly stable until I start downloading, when the UI
becomes unresponsive, sometimes leading to a complete freeze. When the
system does not completely freezes and I'm able to kill the download,
everything seems to go back to normal after killing it, and I am able
to continue to use the computer as long as I do not download anything.
Most of the time either a soft or a hard lockup is detected, but not
always, although the freeze always occurs.
This is the kernel log with lockdep enabled (although sometimes the
problem does not occur with lockdep enabled):
https://gist.github.com/jprvita/3aa2c0c9a66793e1fad1
I have the laptop where this happens as a test machine sitting on my
desk, so I'm available to test any patches or gather more information
if needed. Please advise on how I can help debugging this further.
Regards,
--
João Paulo Rechi Vita
http://about.me/jprvita
On 10/01/2015 08:17 AM, João Paulo Rechi Vita wrote:
> Hello linux-wirelless (cc'ing stable since the original patch had
> cc:stable as well),
>
> I'm experiencing a CPU soft lockup while downloading when rtl8821ae is
> loaded (even when downloading through other adapters) on a vanilla 4.2
> kernel. The problem did not happen on vanilla 4.1. Bisecting shows the
> first bad commit being "rtlwifi: Remove the clear interrupt routine
> from all drivers" (1277fa2ab2f9a624a4b0177119ca13b5fd65edd0).
> Reverting that commit makes the problem go away.
>
> The system is perfectly stable until I start downloading, when the UI
> becomes unresponsive, sometimes leading to a complete freeze. When the
> system does not completely freezes and I'm able to kill the download,
> everything seems to go back to normal after killing it, and I am able
> to continue to use the computer as long as I do not download anything.
> Most of the time either a soft or a hard lockup is detected, but not
> always, although the freeze always occurs.
>
> This is the kernel log with lockdep enabled (although sometimes the
> problem does not occur with lockdep enabled):
> https://gist.github.com/jprvita/3aa2c0c9a66793e1fad1
>
> I have the laptop where this happens as a test machine sitting on my
> desk, so I'm available to test any patches or gather more information
> if needed. Please advise on how I can help debugging this further.
I cannot duplicate your result, and neither can the Realtek team; however, I
have prepared and attached a patch to temporarily re-add the interrupt clear
routine for rtl8821ae. Please try it and report the results.
Larry
Hello Larry,
On 1 October 2015 at 11:42, Larry Finger <[email protected]> wrote:
> On 10/01/2015 08:17 AM, João Paulo Rechi Vita wrote:
>>
>> Hello linux-wirelless (cc'ing stable since the original patch had
>> cc:stable as well),
>>
>> I'm experiencing a CPU soft lockup while downloading when rtl8821ae is
>> loaded (even when downloading through other adapters) on a vanilla 4.2
>> kernel. The problem did not happen on vanilla 4.1. Bisecting shows the
>> first bad commit being "rtlwifi: Remove the clear interrupt routine
>> from all drivers" (1277fa2ab2f9a624a4b0177119ca13b5fd65edd0).
>> Reverting that commit makes the problem go away.
>>
>> The system is perfectly stable until I start downloading, when the UI
>> becomes unresponsive, sometimes leading to a complete freeze. When the
>> system does not completely freezes and I'm able to kill the download,
>> everything seems to go back to normal after killing it, and I am able
>> to continue to use the computer as long as I do not download anything.
>> Most of the time either a soft or a hard lockup is detected, but not
>> always, although the freeze always occurs.
>>
>> This is the kernel log with lockdep enabled (although sometimes the
>> problem does not occur with lockdep enabled):
>> https://gist.github.com/jprvita/3aa2c0c9a66793e1fad1
>>
>> I have the laptop where this happens as a test machine sitting on my
>> desk, so I'm available to test any patches or gather more information
>> if needed. Please advise on how I can help debugging this further.
>
>
> I cannot duplicate your result, and neither can the Realtek team; however, I
> have prepared and attached a patch to temporarily re-add the interrupt clear
> routine for rtl8821ae. Please try it and report the results.
>
With the attached patch the lockup goes away and the system remains
stable during downloads. Let me know if there is anything else you
would like me to test.
Regards,
--
João Paulo Rechi Vita
http://about.me/jprvita