[Intel-wired-lan] suspend/resume broken of igc driver broken on 6.12

[Stephen Hemminger]

On Wed, 5 Feb 2025 12:36:31 +0200
"Lifshits, Vitaly" <vitaly.lifshits at intel.com> wrote:

> On 1/31/2025 3:21 AM, Stephen Hemminger wrote:
> > On Thu, 30 Jan 2025 21:17:30 +0200
> > "Lifshits, Vitaly" <vitaly.lifshits at intel.com> wrote:
> >   
> >> On 1/30/2025 7:11 PM, Stephen Hemminger wrote:  
> >>> I am using:
> >>>
> >>> 5a:00.0 Ethernet controller: Intel Corporation Ethernet Controller I226-LM (rev 04)
> >>> 	Subsystem: Intel Corporation Device 0000
> >>> 	Flags: bus master, fast devsel, latency 0, IRQ 19, IOMMU group 20
> >>> 	Memory at 6c500000 (32-bit, non-prefetchable) [size=1M]
> >>> 	Memory at 6c600000 (32-bit, non-prefetchable) [size=16K]
> >>> 	Capabilities: [40] Power Management version 3
> >>> 	Capabilities: [50] MSI: Enable- Count=1/1 Maskable+ 64bit+
> >>> 	Capabilities: [70] MSI-X: Enable+ Count=5 Masked-
> >>> 	Capabilities: [a0] Express Endpoint, IntMsgNum 0
> >>> 	Capabilities: [100] Advanced Error Reporting
> >>> 	Capabilities: [140] Device Serial Number 58-47-ca-ff-ff-7a-98-3d
> >>> 	Capabilities: [1c0] Latency Tolerance Reporting
> >>> 	Capabilities: [1f0] Precision Time Measurement
> >>> 	Capabilities: [1e0] L1 PM Substates
> >>> 	Kernel driver in use: igc
> >>> 	Kernel modules: igc
> >>>
> >>>
> >>> Using both Debian testing and my own kernel built from 6.12, the igc
> >>> driver appears broken after resume.  
> >>
> >>   From which system state are you resuming?
> >>  
> >>>
> >>> After resuming the device is down and no address present.
> >>> Attempts to set link up manually fail.  
> >>
> >> Did you get any errors in the dmesg log?
> >> What is the firmware version on your device (you can get it by running
> >> ethtool -i)?
> >>  
> >>> If I do rmmod/modprobe of igc it comes back.
> >>>
> >>> Doing a bit of bisectting but it is slow going.  
> >>
> >> Meanwhile, we'll also try to reproduce this issue in our lab.  Could you
> >> share more details about your system so we can create a similar setup?  
> > 
> > Given that error reported is -ENODEV, might be a generic netdev problem not
> > just for igc device.
> >   
> 
> We weren't able to reproduce this issue on our systems, even though we 
> tried several suspend-resume cycles on different kernels and different 
> systems.
> 
> However, a few days ago we received a comment in a BZ about an issue 
> similar to yours. In there adding a short delay in igc_resume function
> https://bugzilla.kernel.org/show_bug.cgi?id=219143
> https://bugzilla.kernel.org/show_bug.cgi?id=219143#c123
> 
> 
> 
> Can you try to see if it fixes your issue as well?

I tried the proposed delay and it had no impact.
Any idea of other things to instrument?