[Intel-wired-lan] [PATCH 1/3] PCI/ASPM: Use the path max in L1 ASPM latency check
Bjorn Helgaas
helgaas at kernel.org
Wed Dec 16 00:08:02 UTC 2020
On Tue, Dec 15, 2020 at 02:09:12PM +0100, Ian Kumlien wrote:
> On Tue, Dec 15, 2020 at 1:40 AM Bjorn Helgaas <helgaas at kernel.org> wrote:
> >
> > On Mon, Dec 14, 2020 at 11:56:31PM +0100, Ian Kumlien wrote:
> > > On Mon, Dec 14, 2020 at 8:19 PM Bjorn Helgaas <helgaas at kernel.org> wrote:
> >
> > > > If you're interested, you could probably unload the Realtek drivers,
> > > > remove the devices, and set the PCI_EXP_LNKCTL_LD (Link Disable) bit
> > > > in 02:04.0, e.g.,
> > > >
> > > > # RT=/sys/devices/pci0000:00/0000:00:01.2/0000:01:00.0/0000:02:04.0
> > > > # echo 1 > $RT/0000:04:00.0/remove
> > > > # echo 1 > $RT/0000:04:00.1/remove
> > > > # echo 1 > $RT/0000:04:00.2/remove
> > > > # echo 1 > $RT/0000:04:00.4/remove
> > > > # echo 1 > $RT/0000:04:00.7/remove
> > > > # setpci -s02:04.0 CAP_EXP+0x10.w=0x0010
> > > >
> > > > That should take 04:00.x out of the picture.
> > >
> > > Didn't actually change the behaviour, I'm suspecting an errata for AMD pcie...
> > >
> > > So did this, with unpatched kernel:
> > > [ ID] Interval Transfer Bitrate Retr Cwnd
> > > [ 5] 0.00-1.00 sec 4.56 MBytes 38.2 Mbits/sec 0 67.9 KBytes
> > > [ 5] 1.00-2.00 sec 4.47 MBytes 37.5 Mbits/sec 0 96.2 KBytes
> > > [ 5] 2.00-3.00 sec 4.85 MBytes 40.7 Mbits/sec 0 50.9 KBytes
> > > [ 5] 3.00-4.00 sec 4.23 MBytes 35.4 Mbits/sec 0 70.7 KBytes
> > > [ 5] 4.00-5.00 sec 4.23 MBytes 35.4 Mbits/sec 0 48.1 KBytes
> > > [ 5] 5.00-6.00 sec 4.23 MBytes 35.4 Mbits/sec 0 45.2 KBytes
> > > [ 5] 6.00-7.00 sec 4.23 MBytes 35.4 Mbits/sec 0 36.8 KBytes
> > > [ 5] 7.00-8.00 sec 3.98 MBytes 33.4 Mbits/sec 0 36.8 KBytes
> > > [ 5] 8.00-9.00 sec 4.23 MBytes 35.4 Mbits/sec 0 36.8 KBytes
> > > [ 5] 9.00-10.00 sec 4.23 MBytes 35.4 Mbits/sec 0 48.1 KBytes
> > > - - - - - - - - - - - - - - - - - - - - - - - - -
> > > [ ID] Interval Transfer Bitrate Retr
> > > [ 5] 0.00-10.00 sec 43.2 MBytes 36.2 Mbits/sec 0 sender
> > > [ 5] 0.00-10.00 sec 42.7 MBytes 35.8 Mbits/sec receiver
> > >
> > > and:
> > > echo 0 > /sys/devices/pci0000:00/0000:00:01.2/0000:01:00.0/link/l1_aspm
> >
> > BTW, thanks a lot for testing out the "l1_aspm" sysfs file. I'm very
> > pleased that it seems to be working as intended.
>
> It was nice to find it for easy disabling :)
>
> > > and:
> > > [ ID] Interval Transfer Bitrate Retr Cwnd
> > > [ 5] 0.00-1.00 sec 113 MBytes 951 Mbits/sec 153 772 KBytes
> > > [ 5] 1.00-2.00 sec 109 MBytes 912 Mbits/sec 276 550 KBytes
> > > [ 5] 2.00-3.00 sec 111 MBytes 933 Mbits/sec 123 625 KBytes
> > > [ 5] 3.00-4.00 sec 111 MBytes 933 Mbits/sec 31 687 KBytes
> > > [ 5] 4.00-5.00 sec 110 MBytes 923 Mbits/sec 0 679 KBytes
> > > [ 5] 5.00-6.00 sec 110 MBytes 923 Mbits/sec 136 577 KBytes
> > > [ 5] 6.00-7.00 sec 110 MBytes 923 Mbits/sec 214 645 KBytes
> > > [ 5] 7.00-8.00 sec 110 MBytes 923 Mbits/sec 32 628 KBytes
> > > [ 5] 8.00-9.00 sec 110 MBytes 923 Mbits/sec 81 537 KBytes
> > > [ 5] 9.00-10.00 sec 110 MBytes 923 Mbits/sec 10 577 KBytes
> > > - - - - - - - - - - - - - - - - - - - - - - - - -
> > > [ ID] Interval Transfer Bitrate Retr
> > > [ 5] 0.00-10.00 sec 1.08 GBytes 927 Mbits/sec 1056 sender
> > > [ 5] 0.00-10.00 sec 1.07 GBytes 923 Mbits/sec receiver
> > >
> > > But this only confirms that the fix i experience is a side effect.
> > >
> > > The original code is still wrong :)
> >
> > What exactly is this machine? Brand, model, config? Maybe you could
> > add this and a dmesg log to the buzilla? It seems like other people
> > should be seeing the same problem, so I'm hoping to grub around on the
> > web to see if there are similar reports involving these devices.
>
> ASUS Pro WS X570-ACE with AMD Ryzen 9 3900X
Possible similar issues:
https://forums.unraid.net/topic/94274-hardware-upgrade-woes/
https://forums.servethehome.com/index.php?threads/upgraded-my-home-server-from-intel-to-amd-virtual-disk-stuck-in-degraded-unhealty-state.25535/ (Windows)
> > https://bugzilla.kernel.org/show_bug.cgi?id=209725
> >
> > Here's one that is superficially similar:
> > https://linux-hardware.org/index.php?probe=e5f24075e5&log=lspci_all
> > in that it has a RP -- switch -- I211 path. Interestingly, the switch
> > here advertises <64us L1 exit latency instead of the <32us latency
> > your switch advertises. Of course, I can't tell if it's exactly the
> > same switch.
>
> Same chipset it seems
>
> I'm running bios version:
> Version: 2206
> Release Date: 08/13/2020
>
> ANd latest is:
> Version 3003
> 2020/12/07
>
> Will test upgrading that as well, but it could be that they report the
> incorrect latency of the switch - I don't know how many things AGESA
> changes but... It's been updated twice since my upgrade.
I wouldn't be surprised if the advertised exit latencies are writable
by the BIOS because it probably depends on electrical characteristics
outside the switch. If so, it's possible ASUS just screwed it up.
More information about the Intel-wired-lan
mailing list