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From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Keith Busch <kbusch@kernel.org>
Cc: "Busch, Keith" <keith.busch@intel.com>,
	Christoph Hellwig <hch@lst.de>, Sagi Grimberg <sagi@grimberg.me>,
	"linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
	Mario Limonciello <Mario.Limonciello@dell.com>,
	Kai Heng Feng <kai.heng.feng@canonical.com>,
	Linux PM <linux-pm@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [Regression] Commit "nvme/pci: Use host managed power state for suspend" has problems
Date: Thu, 25 Jul 2019 21:48:57 +0200	[thread overview]
Message-ID: <2428826.VBuqOhikiK@kreacher> (raw)
In-Reply-To: <20190725145209.GA6949@localhost.localdomain>

On Thursday, July 25, 2019 4:52:10 PM CEST Keith Busch wrote:
> On Thu, Jul 25, 2019 at 02:51:41AM -0700, Rafael J. Wysocki wrote:
> > Hi Keith,
> > 
> > Unfortunately,
> > 
> > commit d916b1be94b6dc8d293abed2451f3062f6af7551
> > Author: Keith Busch <keith.busch@intel.com>
> > Date:   Thu May 23 09:27:35 2019 -0600
> > 
> >     nvme-pci: use host managed power state for suspend
> > 
> > doesn't universally improve things.  In fact, in some cases it makes things worse.
> > 
> > For example, on the Dell XPS13 9380 I have here it prevents the processor package
> > from reaching idle states deeper than PC2 in suspend-to-idle (which, of course, also
> > prevents the SoC from reaching any kind of S0ix).
> > 
> > That can be readily explained too.  Namely, with the commit above the NVMe device
> > stays in D0 over suspend/resume, so the root port it is connected to also has to stay in
> > D0 and that "blocks" package C-states deeper than PC2.
> > 
> > In order for the root port to be able to go to D3, the device connected to it also needs
> > to go into D3, so it looks like (at least on this particular machine, but maybe in
> > general), both D3 and the NVMe-specific PM are needed.
> > 
> > I'm not sure what to do here, because evidently there are systems where that commit
> > helps.  I was thinking about adding a module option allowing the user to override the
> > default behavior which in turn should be compatible with 5.2 and earlier kernels.
> 
> Darn, that's too bad. I don't think we can improve one thing at the
> expense of another, so unless we find an acceptable criteria to select
> what low power mode to use, I would be inclined to support a revert or
> a kernel option to default to the previous behavior.
> 
> One thing we might check before using NVMe power states is if the lowest
> PS is non-operational with MP below some threshold. What does your device
> report for:
> 
>   nvme id-ctrl /dev/nvme0

NVME Identify Controller:
vid     : 0x1c5c
ssvid   : 0x1c5c
sn      : MS92N171312902J0N   
mn      : PC401 NVMe SK hynix 256GB               
fr      : 80007E00
rab     : 2
ieee    : ace42e
cmic    : 0
mdts    : 5
cntlid  : 1
ver     : 10200
rtd3r   : 7a120
rtd3e   : 1e8480
oaes    : 0x200
ctratt  : 0
oacs    : 0x17
acl     : 7
aerl    : 3
frmw    : 0x14
lpa     : 0x2
elpe    : 255
npss    : 4
avscc   : 0x1
apsta   : 0x1
wctemp  : 352
cctemp  : 354
mtfa    : 0
hmpre   : 0
hmmin   : 0
tnvmcap : 0
unvmcap : 0
rpmbs   : 0
edstt   : 10
dsto    : 0
fwug    : 0
kas     : 0
hctma   : 0
mntmt   : 0
mxtmt   : 0
sanicap : 0
hmminds : 0
hmmaxd  : 0
nsetidmax : 0
anatt   : 0
anacap  : 0
anagrpmax : 0
nanagrpid : 0
sqes    : 0x66
cqes    : 0x44
maxcmd  : 0
nn      : 1
oncs    : 0x1f
fuses   : 0x1
fna     : 0
vwc     : 0x1
awun    : 7
awupf   : 7
nvscc   : 1
acwu    : 7
sgls    : 0
mnan    : 0
subnqn  : 
ioccsz  : 0
iorcsz  : 0
icdoff  : 0
ctrattr : 0
msdbd   : 0
ps    0 : mp:6.00W operational enlat:5 exlat:5 rrt:0 rrl:0
          rwt:0 rwl:0 idle_power:- active_power:-
ps    1 : mp:3.80W operational enlat:30 exlat:30 rrt:1 rrl:1
          rwt:1 rwl:1 idle_power:- active_power:-
ps    2 : mp:2.40W operational enlat:100 exlat:100 rrt:2 rrl:2
          rwt:2 rwl:2 idle_power:- active_power:-
ps    3 : mp:0.0700W non-operational enlat:1000 exlat:1000 rrt:3 rrl:3
          rwt:3 rwl:3 idle_power:- active_power:-
ps    4 : mp:0.0070W non-operational enlat:1000 exlat:5000 rrt:3 rrl:3
          rwt:3 rwl:3 idle_power:- active_power:-




  reply	other threads:[~2019-07-25 19:49 UTC|newest]

Thread overview: 75+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-25  9:51 Rafael J. Wysocki
2019-07-25 14:02 ` Kai-Heng Feng
2019-07-25 16:23   ` Mario.Limonciello
2019-07-25 17:03     ` Rafael J. Wysocki
2019-07-25 17:23       ` Mario.Limonciello
2019-07-25 18:20       ` Kai-Heng Feng
2019-07-25 19:09         ` Mario.Limonciello
2019-07-30 10:45       ` Rafael J. Wysocki
2019-07-30 14:41         ` Keith Busch
2019-07-30 17:14           ` Mario.Limonciello
2019-07-30 18:50             ` Kai-Heng Feng
2019-07-30 19:19               ` Keith Busch
2019-07-30 21:05                 ` Mario.Limonciello
2019-07-30 21:31                   ` Keith Busch
2019-07-31 21:25                     ` Rafael J. Wysocki
2019-07-31 22:19                       ` Keith Busch
2019-07-31 22:33                         ` Rafael J. Wysocki
2019-08-01  9:05                           ` Kai-Heng Feng
2019-08-01 17:29                             ` Rafael J. Wysocki
2019-08-01 19:05                               ` Mario.Limonciello
2019-08-01 22:26                                 ` Rafael J. Wysocki
2019-08-02 10:55                                   ` Kai-Heng Feng
2019-08-02 11:04                                     ` Rafael J. Wysocki
2019-08-05 19:13                                       ` Kai-Heng Feng
2019-08-05 21:28                                         ` Rafael J. Wysocki
2019-08-06 14:02                                           ` Mario.Limonciello
2019-08-06 15:00                                             ` Rafael J. Wysocki
2019-08-07 10:29                                               ` Rafael J. Wysocki
2019-08-01 20:22                             ` Keith Busch
2019-08-07  9:48                         ` Rafael J. Wysocki
2019-08-07 10:45                           ` Christoph Hellwig
2019-08-07 10:54                             ` Rafael J. Wysocki
2019-08-07  9:53                         ` [PATCH] nvme-pci: Do not prevent PCI bus-level PM from being used Rafael J. Wysocki
2019-08-07 10:14                           ` Rafael J. Wysocki
2019-08-07 10:43                           ` Christoph Hellwig
2019-08-07 14:37                           ` Keith Busch
2019-08-08  8:36                         ` [PATCH] nvme-pci: Allow PCI bus-level PM to be used if ASPM is disabled Rafael J. Wysocki
2019-08-08  8:48                           ` Christoph Hellwig
2019-08-08  9:06                             ` Rafael J. Wysocki
2019-08-08 10:03                         ` [PATCH v2 0/2] " Rafael J. Wysocki
2019-08-08 10:06                           ` [PATCH v2 1/2] PCI: PCIe: ASPM: Introduce pcie_aspm_enabled_mask() Rafael J. Wysocki
2019-08-08 13:15                             ` Bjorn Helgaas
2019-08-08 14:48                               ` Rafael J. Wysocki
2019-08-08 10:10                           ` [PATCH v2 2/2] nvme-pci: Allow PCI bus-level PM to be used if ASPM is disabled Rafael J. Wysocki
2019-08-08 13:43                             ` Bjorn Helgaas
2019-08-08 14:47                               ` Rafael J. Wysocki
2019-08-08 17:06                                 ` Rafael J. Wysocki
2019-08-08 18:39                                 ` Bjorn Helgaas
2019-08-08 20:01                                   ` Keith Busch
2019-08-08 20:05                                   ` Mario.Limonciello
2019-08-08 20:41                                   ` Rafael J. Wysocki
2019-08-09  4:47                                     ` Bjorn Helgaas
2019-08-09  8:04                                       ` Rafael J. Wysocki
2019-08-08 21:51                         ` [PATCH v3 0/2] " Rafael J. Wysocki
2019-08-08 21:55                           ` [PATCH v3 1/2] PCI: PCIe: ASPM: Introduce pcie_aspm_enabled() Rafael J. Wysocki
2019-08-09  4:50                             ` Bjorn Helgaas
2019-08-09  8:00                               ` Rafael J. Wysocki
2019-10-07 22:34                             ` Bjorn Helgaas
2019-10-08  9:27                               ` Rafael J. Wysocki
2019-10-08 21:16                                 ` Bjorn Helgaas
2019-10-08 22:54                                   ` Rafael J. Wysocki
2019-10-09 12:49                                     ` Bjorn Helgaas
2019-08-08 21:58                           ` [PATCH v3 2/2] nvme-pci: Allow PCI bus-level PM to be used if ASPM is disabled Rafael J. Wysocki
2019-08-08 22:13                           ` [PATCH v3 0/2] " Keith Busch
2019-08-09  8:05                             ` Rafael J. Wysocki
2019-08-09 14:52                               ` Keith Busch
2019-07-25 16:59   ` [Regression] Commit "nvme/pci: Use host managed power state for suspend" has problems Rafael J. Wysocki
2019-07-25 14:52 ` Keith Busch
2019-07-25 19:48   ` Rafael J. Wysocki [this message]
2019-07-25 19:52     ` Keith Busch
2019-07-25 20:02       ` Rafael J. Wysocki
2019-07-26 14:02         ` Kai-Heng Feng
2019-07-27 12:55           ` Rafael J. Wysocki
2019-07-29 15:51             ` Mario.Limonciello
2019-07-29 22:05               ` Rafael J. Wysocki

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