Re: PROBLEM: 5.3.0-rc* causes iwlwifi failure

[Chris Clayton]

Thanks, Stuart.

On 18/08/2019 11:55, Stuart Little wrote:
> On Sun, Aug 18, 2019 at 09:17:59AM +0100, Chris Clayton wrote:
>>
>>
>> On 17/08/2019 22:44, Stuart Little wrote:
>>> After some private coaching from Serge Belyshev on git-revert I can confirm that reverting that commit atop the current tree resolves the issue (the wifi card scans for and finds networks just fine, no dmesg errors reported, etc.).
>>>
>>
>> I've reported the "Microcode SW error detected" issue too, but, wrongly, only to LKML. I'll point that thread to this
>> one. I've also been experiencing my network stopping working after suspend resume, but haven't got round to reporting
>> that yet.
>>
>> What was the git magic that you acquired to revert the patch, please?
>>

By following the advice below, I reverted 4fd445a2c855bbcab81fbe06d110e78dbd974a5b and using the resultant kernel I
haven't seen the "Microcode SW error detected" again. I am, however, still experiencing the problem of my network not
working after resume from suspend. I've reported it to LKML, so it can be followed there should anyone need/want to.

> 
> $ git revert <offending commit>
> 
> This will fail as noted, but will place in a revert mode where you can fix the errors.
> 
> $ git status
> 
> will show (it did in my case, for the latest Linux tree at the time I did this) a modified file
> 
> drivers/net/wireless/intel/iwlwifi/mvm/fw.c
> 
> to be committed without issue and a conflicted file
> 
> drivers/net/wireless/intel/iwlwifi/mvm/nvm.c
> 
> whose conflicts you have to first resolve.
> 
> I then opened that conflicted file in a text editor and simply removed everything between the lines
> 
> <<<<<<< HEAD
> 
> and 
> 
>>>>>>>> parent of 4fd445a2c855... iwlwifi: mvm: Add log information about SAR status
> 
> (inclusive). This resolved the conflict, whereupon
> 
> $ git revert --continue
> 
> and
> 
> $ git commit -a
> 
> will finish the reversion. 
> 
>>> On Sat, Aug 17, 2019 at 11:59:59AM +0300, Serge Belyshev wrote:
>>>>
>>>>> I am on an Intel(R) Core(TM) i7-7500U CPU @ 2.70GHz running Linux
>>>>> x86_64 (Slackware), with a custom-compiled 5.3.0-rc4 (.config
>>>>> attached).
>>>>>
>>>>> I am using the Intel wifi adapter on this machine:
>>>>>
>>>>> 02:00.0 Network controller: Intel Corporation Device 24fb (rev 10)
>>>>>
>>>>> with the iwlwifi driver. I am attaching the output to 'lspci -vv -s
>>>>> 02:00.0' as the file device-info.
>>>>>
>>>>> All 5.3.0-rc* versions I have tried (including rc4) cause multiple
>>>>> dmesg iwlwifi-related errors (dmesg attached). Examples:
>>>>>
>>>>> iwlwifi 0000:02:00.0: Failed to get geographic profile info -5
>>>>> iwlwifi 0000:02:00.0: Microcode SW error detected.  Restarting 0x82000000
>>>>> iwlwifi 0000:02:00.0: 0x00000038 | BAD_COMMAND
>>>>>
>>>>
>>>> I have my logs filled with similar garbage throughout 5.3-rc*. Also
>>>> since 5.3-rcsomething not only it WARNS in dmesg about firmware failure,
>>>> but completely stops working after suspend/resume cycle.
>>>>
>>>> It looks like that:
>>>>
>>>> commit 4fd445a2c855bbcab81fbe06d110e78dbd974a5b
>>>> Author: Haim Dreyfuss <haim.dreyfuss@xxxxxxxxx>
>>>> Date:   Thu May 2 11:45:02 2019 +0300
>>>>
>>>>     iwlwifi: mvm: Add log information about SAR status
>>>>     
>>>>     Inform users when SAR status is changing.
>>>>     
>>>>     Signed-off-by: Haim Dreyfuss <haim.dreyfuss@xxxxxxxxx>
>>>>     Signed-off-by: Luca Coelho <luciano.coelho@xxxxxxxxx>
>>>>
>>>>
>>>> is the culprit. (manually) reverting it on top of 5.3-rc4 makes
>>>> everything work again.
>>>