linux-pci.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Lukas Wunner <lukas@wunner.de>
To: Stefan Roese <sr@denx.de>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>,
	linux-pci@vger.kernel.org, Bjorn Helgaas <bhelgaas@google.com>
Subject: Re: [RFC PATCH] PCI: pciehp: Add module parameter to enable debouncing of HP link events
Date: Fri, 2 Feb 2018 14:47:10 +0100	[thread overview]
Message-ID: <20180202134710.GA24377@wunner.de> (raw)
In-Reply-To: <a91f095b-87d3-d1ab-7dea-e9a0bcfd9e01@denx.de>

On Fri, Feb 02, 2018 at 02:38:34PM +0100, Stefan Roese wrote:
> > On Tue, Jan 30, 2018 at 09:41:21AM +0100, Stefan Roese wrote:
> >> Hotplugging of some PCIe devices on our platform sometimes leads to a
> >> bounce of link-up and link-down events, resulting in problems in the
> >> corresponding PCI drivers.
> >>
> >> Here an example of such a hotplug event bounce for a AHCI PCIe card:
> >> ...
> >> pciehp 0000:00:1c.1:pcie004: Slot(1): Card present
> >> pciehp 0000:00:1c.1:pcie004: Slot(1): Link Up
> >> pciehp 0000:00:1c.1:pcie004: Slot(1): Link Up event ignored; already powering on
> >> pciehp 0000:00:1c.1:pcie004: Slot(1): Link Down
> >> pciehp 0000:00:1c.1:pcie004: Slot(1): Card present
> >> pciehp 0000:00:1c.1:pcie004: Slot(1): Link Up
> 
> I'm open for other / better ideas on how to solve this situation, we
> are seeing on our systems.

If a Link Up event is received and there is already a Link Up / Link Down
pair in the queue, the Link Down event can be dequeued and the newly
received Link Up event need not be queued.

Same if a Link Down event is received and there is already a Link Down /
Link Up pair in the queue.

Thanks,

Lukas

  reply	other threads:[~2018-02-02 13:54 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-30  8:41 [RFC PATCH] PCI: pciehp: Add module parameter to enable debouncing of HP link events Stefan Roese
2018-01-30 10:28 ` Mika Westerberg
2018-02-02 13:38   ` Stefan Roese
2018-02-02 13:47     ` Lukas Wunner [this message]
2018-02-02 14:44       ` Stefan Roese
2018-02-02 19:20         ` Bjorn Helgaas
2018-02-02 13:56     ` Mika Westerberg
2018-02-02 14:50       ` Stefan Roese
2018-02-02 15:11         ` Mika Westerberg

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:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

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

  git send-email \
    --in-reply-to=20180202134710.GA24377@wunner.de \
    --to=lukas@wunner.de \
    --cc=bhelgaas@google.com \
    --cc=linux-pci@vger.kernel.org \
    --cc=mika.westerberg@linux.intel.com \
    --cc=sr@denx.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* 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).