This bug was fixed in the package linux-oem-5.10 - 5.10.0-1052.54
---------------
linux-oem-5.10 (5.10.0-1052.54) focal; urgency=medium
* focal/linux-oem-5.10: 5.10.0-1052.54 -proposed tracker (LP:
#1949843)
* creat09 from ubuntu_ltp_syscalls and cve-2018-13405 from ubuntu_ltp/cve
failed with XFS (LP: #1950239)
- xfs: fix up non-directory creation in SGID directories
* Let NVMe with HMB use native power control again (LP: #1950042)
- nvme-pci: use attribute group for cmb sysfs
- nvme-pci: cmb sysfs: one file, one value
- nvme-pci: disable hmb on idle suspend
- nvme: allow user toggling hmb usage
* require CAP_NET_ADMIN to attach N_HCI ldisc (LP: #1949516)
- Bluetooth: hci_ldisc: require CAP_NET_ADMIN to attach N_HCI ldisc
-- Chia-Lin Kao (AceLan) <acelan....@canonical.com> Tue, 23 Nov 2021
15:29:37 +0800
** Changed in: linux-oem-5.10 (Ubuntu Focal)
Status: Fix Committed => Fix Released
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https://bugs.launchpad.net/bugs/1950042
Title:
Let NVMe with HMB use native power control again
Status in HWE Next:
New
Status in linux package in Ubuntu:
Incomplete
Status in linux-oem-5.10 package in Ubuntu:
Invalid
Status in linux-oem-5.13 package in Ubuntu:
Invalid
Status in linux-oem-5.14 package in Ubuntu:
Invalid
Status in linux source package in Focal:
Won't Fix
Status in linux-oem-5.10 source package in Focal:
Fix Released
Status in linux-oem-5.13 source package in Focal:
Fix Released
Status in linux-oem-5.14 source package in Focal:
Fix Released
Status in linux source package in Hirsute:
Fix Committed
Status in linux-oem-5.10 source package in Hirsute:
Invalid
Status in linux-oem-5.13 source package in Hirsute:
Invalid
Status in linux-oem-5.14 source package in Hirsute:
Invalid
Status in linux source package in Impish:
Fix Committed
Status in linux-oem-5.10 source package in Impish:
Invalid
Status in linux-oem-5.13 source package in Impish:
Invalid
Status in linux-oem-5.14 source package in Impish:
Invalid
Bug description:
Impact]
NVMe with HMB may still do DMA during suspend, so there was a commit
that put the NVMe to PCI D3 during suspend to prevent DMA activities.
However, this makes them consumes much more power because modern NVMe
requires to stay at PCI D0 to make its natve power control work.
[Fix]
Instead of put the NVMe to PCI D3 and reset it afterward, simply disable
HMB and re-enable HMB, for suspend and resume respectively.
[Test]
On affected system, Intel SoC can only reach PC3 during suspend.
With the SRU applied, the Intel SoC can reach PC10 and SLP_S0 and use
significant less power.
[Where problems could occur]
The original approach, i.e. disable NVMe and put it to PCI D3 to prevent
DMA activies, was just a precaution. There wasn't any case that
indicates it happens in practice.
This is a different approach to the same problem, which is a theoretical
problem.
To manage notifications about this bug go to:
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