APPLIED [O] Re: [SRU][N/O/unstable][PATCH v2 0/2] Enable ASPM for nvme controller when working in RAID on mode

[Timo Aaltonen]

Hui Wang kirjoitti 19.8.2024 klo 5.59:
> BugLink: https://bugs.launchpad.net/bugs/2072679
> 
> In the v2:
> Thanks for Timo to point out, there is the same problem for
> lunar-generic and mantic-generic kernels, and we applied to similar
> UBUNTU SAUCE patches to those kernels, but somehow we forgot to
> apply the patches to unstable at that time, hence we have regression
> for this issue in N/O/..., the tracking bug for L/M is:
> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2034504
> 
> short-term plan:
> SRU the SAUCE patches to N/O/unstable, fix the regression on those
> Dell machines ASAP.
> long-term plan:
> Kai-heng will ping and discuss with linux-pci maintainers, modify
> the patch as maintainers request, once the formal patches are merged
> to upstream kernel, I will revert the SAUCE patches from N/O/unstable
> and SRU the formal patches to these kernels.
> 
> 
> [Impact]
> The NVME controller works in RAID on mode by default on some Dell
> machines, and in this case, the PCIE ASPM couldn't be enabled, and
> as a result the system idle can't enter deep idle states. This issue
> not only impacts ubuntu users but also impacts our Dell OEM projects.
> 
> 
> [Fix]
> pick 2 commits from linux-pci mailist
> 
> [Test]
> After running the patched kernel, we could run 'sudo lspci -nnvv'
> and check "Non-Volatile memory controller":
>                 LnkCtl: ASPM L1 Enabled;
> 
> And check idle states, we could see the system could enter deep idle:
> $ sudo cat /sys/kernel/debug/pmc_core/package_cstate_show
> Package C2 : 55740989
> Package C3 : 4656373
> Package C6 : 43325041
> Package C7 : 6687655
> Package C8 : 44948950
> Package C9 : 1693
> Package C10 : 92865596
> 
> [Where problems could occur]
> Because the patchset is not accepted by upstream yet, it is a bit
> risky to merge the patchset to ubuntu kernel. And the patch only
> impacts vmd driver, hence if there is regression, it could only be
> in the nvme driver with RAID on mode. The regression possibility is
> very low because we already tested the patch on many Dell, lenovo
> machines, there is no regression so far.
> 
> 
> Kai-Heng Feng (2):
>    UBUNTU: SAUCE: PCI: ASPM: Allow OS to configure ASPM where BIOS is
>      incapable of
>    UBUNTU: SAUCE: PCI: vmd: Let OS control ASPM for devices under VMD
>      domain
> 
>   drivers/pci/controller/vmd.c | 2 ++
>   drivers/pci/pcie/aspm.c      | 8 ++++++--
>   include/linux/pci.h          | 1 +
>   3 files changed, 9 insertions(+), 2 deletions(-)
> 

applied to oracular, thanks

-- 
t