A question about hotplug and suspend-resume functionallity

A question about hotplug and suspend-resume functionallity

[Igor Bezukh]

Hi,


We are testing Intel Gigabit adapter driver (igb) under Fedora 20, kernel 3.14.4 for the following use-case:

(*) Adapter is connected to the PCIE slot
(*) We put the system under suspend by running pm-suspend from user-space
(*) Remove the adapter from the PCIE slot
(*) Wake up the system

Currently, we got kernel panics and the system gets stuck.

My questions are - 
1) in order to support hot-unplugging in igb driver, should I implement the check of device presence in igb_resume
function?

2) After the system wakes up, I see in dmesg that the PCI device function igb refuses to change power state and remains in PCI power state D3.
     can I assume that after suspend-resume if the function remains in D3 and refuses to move to D1 then hot-unplug event has occured?

Thanks and BR,
Igor Bezukh

Re: A question about hotplug and suspend-resume functionallity

[Greg KH]

On Tue, Jul 08, 2014 at 05:02:57PM +0000, Igor Bezukh wrote:
> Hi,
> 
> 
> We are testing Intel Gigabit adapter driver (igb) under Fedora 20, kernel 3.14.4 for the following use-case:
> 
> (*) Adapter is connected to the PCIE slot
> (*) We put the system under suspend by running pm-suspend from user-space
> (*) Remove the adapter from the PCIE slot
> (*) Wake up the system
> 
> Currently, we got kernel panics and the system gets stuck.

Not good, have you sent the kernel panic to the netdev@vger.kernel.org
mailing list and cc:ed the driver authors?

> My questions are - 
> 1) in order to support hot-unplugging in igb driver, should I implement the check of device presence in igb_resume
> function?
> 
> 2) After the system wakes up, I see in dmesg that the PCI device function igb refuses to change power state and remains in PCI power state D3.
>      can I assume that after suspend-resume if the function remains in D3 and refuses to move to D1 then hot-unplug event has occured?

These questions would be best acked on the above list, the developers
there should be able to help you out.

good luck,

greg k-h