archive mirror
 help / color / mirror / Atom feed
From: Keith Busch <>
To: "Jason A. Donenfeld" <>
Subject: Re: spammy dmesg about fluctuating pcie bandwidth on 5.9
Date: Wed, 7 Oct 2020 09:46:07 -0700	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

On Wed, Oct 07, 2020 at 06:09:06PM +0200, Jason A. Donenfeld wrote:
> Since 5.9 I've been seeing lots of the below in my logs. I'm wondering
> if this is a case of "ASPM finally working properly," or if I'm
> actually running into aberrant behavior that I should look into
> further. I run with `pcie_aspm=force pcie_aspm.policy=powersave` on my
> command line. But I wasn't seeing these messages in 5.8.
> [79960.801929] pcieport 0000:04:00.0: 31.504 Gb/s available PCIe bandwidth, limited by 8.0 GT/s PCIe x4 link at 0000:00:1b.4 (capable of 1984.941 Gb/s with 32.0 GT/s PCIe x63 link)

A x63 gen5 capable link?! No such encoding exists, so something is
definitely wrong. Looks like all 1's was returned when reading the link
capabilities register, as that equals the mask's 0x3f value. The code
ought to skip reporting a device returning all 1's.

  reply	other threads:[~2020-10-07 16:46 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-07 16:09 spammy dmesg about fluctuating pcie bandwidth on 5.9 Jason A. Donenfeld
2020-10-07 16:46 ` Keith Busch [this message]
2020-10-07 17:02 ` Bjorn Helgaas
2020-10-09 14:32   ` Alex G.
2020-10-09 15:05     ` Bjorn Helgaas
     [not found] <>
2020-10-12 22:03 ` Bjorn Helgaas
2020-10-14 10:31   ` Jason A. Donenfeld

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).