Enable LTR for endpoints behind VMD
Bug #1896598 reported by
Kai-Heng Feng
This bug affects 1 person
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
HWE Next |
Fix Released
|
Undecided
|
Unassigned | ||
linux (Ubuntu) |
Fix Released
|
Medium
|
Unassigned | ||
Focal |
Won't Fix
|
Undecided
|
Unassigned | ||
Groovy |
Fix Released
|
Medium
|
Unassigned | ||
linux-oem-5.6 (Ubuntu) |
Invalid
|
Undecided
|
Unassigned | ||
Focal |
Fix Released
|
Medium
|
Unassigned | ||
Groovy |
Invalid
|
Undecided
|
Unassigned |
Bug Description
[Impact]
PCIe links behind VMD may not be able to reach ASPM L1.2, because PCIe
Link Tolenrence Reporting doesn't get programmed with a sensible value.
[Fix]
Temporarily hardcode LTR value, which is used by Windows, for NVMe
devices behind VMD.
[Test]
With the patch applied, PCIe links can reach ASPM L1.2, hence the entire
Intel SoC can reach deeper power saving state.
[Regression Potential]
This patch targets specifically Intel Tigerlake VMD bridges, so there
won't be any regression since they are not on the market yet.
Changed in linux (Ubuntu Focal): | |
status: | New → Won't Fix |
Changed in linux-oem-5.6 (Ubuntu Groovy): | |
status: | New → Won't Fix |
status: | Won't Fix → Invalid |
Changed in linux (Ubuntu Groovy): | |
importance: | Undecided → Medium |
Changed in linux-oem-5.6 (Ubuntu Focal): | |
importance: | Undecided → Medium |
status: | New → Confirmed |
Changed in linux (Ubuntu Groovy): | |
status: | New → Confirmed |
tags: | added: oem-priority originate-from-1890125 somerville |
Changed in linux-oem-5.6 (Ubuntu Focal): | |
status: | Confirmed → Fix Committed |
tags: |
added: verification-done-focal removed: verification-needed-focal |
tags: | added: originate-from-1891607 |
Changed in linux-oem-5.6 (Ubuntu): | |
status: | New → Invalid |
Changed in hwe-next: | |
status: | New → Fix Released |
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This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification- needed- focal' to 'verification- done-focal' . If the problem still exists, change the tag 'verification- needed- focal' to 'verification- failed- focal'.
If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.
See https:/ /wiki.ubuntu. com/Testing/ EnableProposed for documentation how to enable and use -proposed. Thank you!