On 7/28/2025 12:20 AM, Jason Gunthorpe wrote:
On Sun, Jul 27, 2025 at 08:48:26PM +0800, Ethan Zhao wrote:
At least, we can do some attempt in DPC and Hot-plug driver, and then
push the hardware specification update to provide pre-reset notification for
DPC & hotplug. does it make sense ?
I think DPC is a different case..
More complex and practical case.
If we get a DPC we should also push the iommu into blocking, disable
ATS and abandon any outstanding ATC invalidations as part of
recovering from the DPC. Once everythings is cleaned up we can set the
Yup, even pure software resets, there might be ATC invalidation pending
(in software queue or HW queue).
iommu back up again and allow the driver to recover the device.
I think the current series is a good step along that path, but we'd
also need to improve the drivers to handle abandonding/aborting the
ATC invalidations.
Also aborting ATC invalidation works as per-condition for DPC or
Hot-plug cases. agree, such improvement seems necessary.
IMHO DPC and SW initiated reset are separate projects.
Of Course, Rome wasn't built in a day; I endorse the success philosophy
of restricting project scope. The discussion is purely focused on
technical methodology.
Thanks,
Ethan
Jason
