Re: [PATCH v4 3/8] drm/xe/survivability: Guard runtime survivability enable against unbind

["Tauro, Riana" <riana.tauro@intel.com>]

On 11-11-2026 11:09, Raag Jadav wrote:
> On Wed, Nov 11, 2026 at 10:13:44AM +0530, Tauro, Riana wrote:
>> On 10-11-2026 18:21, Raag Jadav wrote:
>>> On Fri, Nov 06, 2026 at 12:49:48PM +0530, Riana Tauro wrote:
>>>> Runtime surivability mode creates sysfs and declares the device as
>>>> wedged in a worker thread. This can race with unbind.
>>>>
>>>> During unbind, devres actions such as disabling the worker run as part of
>>>> teardown. A runtime survivability enable that is still in flight or gets
>>>> scheduled in that window can create the survivability sysfs entries while
>>>> the device is being removed. This is incorrect, as runtime survivability mode
>>>> must not be entered once during devres teardown.
>>>>
>>>> Use the DRM device enter/exit protection so that the enable path
>>>> synchronizes with device unplug and returns early if the device is
>>>> already being unbound.
>>> I'm a bit lost here. Doesn't disable_work_sync() already guarantee this?
>> If the worker is already queued and there is a unbind in progress. The
>> disable work sync from devm
>> action waits for the worker to complete. This causes the device to enter
>> survivability mode during unbind
>> which is not intended.
> Wouldn't the survivability stuff still land on devres and get cleaned
> up anyway?

devres_release_all running as part of unbind copies all the devres nodes 
into a todo list and then
releases them. If during release, we add a new devres that will not be 
cleared during unbind
which can cause stale sysfs.

Riana

>
> Raag