Re: PROBLEM: 5.3.0-rc* causes iwlwifi failure

[Stuart Little <achirvasub@gmail.com>]

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?
> 

$ 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@intel.com>
> >> 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@intel.com>
> >>     Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
> >>
> >>
> >> is the culprit. (manually) reverting it on top of 5.3-rc4 makes
> >> everything work again.
> >