linux-pci.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: <dan.j.williams@intel.com>
To: Christoph Hellwig <hch@lst.de>, Lukas Wunner <lukas@wunner.de>
Cc: Christoph Hellwig <hch@lst.de>,
	Bjorn Helgaas <helgaas@kernel.org>,
	"Dmitry Torokhov" <dmitry.torokhov@gmail.com>,
	<linux-pci@vger.kernel.org>,
	"Yaron Avizrat" <yaron.avizrat@intel.com>,
	Koby Elbaz <koby.elbaz@intel.com>,
	Konstantin Sinyuk <konstantin.sinyuk@intel.com>,
	Davidlohr Bueso <dave@stgolabs.net>,
	Jonathan Cameron <jonathan.cameron@huawei.com>,
	"Dave Jiang" <dave.jiang@intel.com>,
	Alison Schofield <alison.schofield@intel.com>,
	Vishal Verma <vishal.l.verma@intel.com>,
	Ira Weiny <ira.weiny@intel.com>,
	"Dan Williams" <dan.j.williams@intel.com>,
	Even Xu <even.xu@intel.com>, Xinpeng Sun <xinpeng.sun@intel.com>,
	Jean Delvare <jdelvare@suse.com>,
	Alexander Usyskin <alexander.usyskin@intel.com>,
	Adrian Hunter <adrian.hunter@intel.com>,
	"Keith Busch" <kbusch@kernel.org>, Jens Axboe <axboe@kernel.dk>,
	Sagi Grimberg <sagi@grimberg.me>,
	Alan Stern <stern@rowland.harvard.edu>,
	"K. Y. Srinivasan" <kys@microsoft.com>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	"Wei Liu" <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
	Stuart Hayes <stuart.w.hayes@gmail.com>,
	David Jeffery <djeffery@redhat.com>,
	"Jeremy Allison" <jallison@ciq.com>
Subject: Re: [PATCH] PCI: Allow drivers to opt in to async probing
Date: Mon, 14 Jul 2025 23:35:35 -0700	[thread overview]
Message-ID: <6875f6b72057a_11344100f1@dwillia2-mobl4.notmuch> (raw)
In-Reply-To: <20250715061309.GB18672@lst.de>

Christoph Hellwig wrote:
> On Mon, Jul 14, 2025 at 04:20:03PM +0200, Lukas Wunner wrote:
> > I guess what happens in your case is, *after* initial probing has
> > concluded and user space is up and running, a driver is unbound
> > from the device and another driver is subsequently re-bound.
> > E.g. "nvme" is unbound and "virtio-pci" is bound instead.
> 
> How?  This is a non-modular simply kernel running on kvm.  There
> should be no re-binding, and binding nvme devices to virtio of course
> also doesn't make sense.

I too could have swore I see async behavior with cxl_pci. I believe this
patch is only affecting async behavior when the driver is loaded before
initial arrival of the PCI device.

For the typical modular driver case the late arriving driver also
arranges async probing. Lo and behold on current upstream:

[   13.002750] __driver_attach: pci 0000:35:00.0: probing driver cxl_pci asynchronously

...so this patch is only a change in behavior for built-in drivers
loaded before PCI initial scan afaics.

  reply	other threads:[~2025-07-15  6:36 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-07-04  7:38 [PATCH] PCI: Allow drivers to opt in to async probing Lukas Wunner
2025-07-08 23:11 ` Bjorn Helgaas
2025-07-14 13:45 ` Christoph Hellwig
2025-07-14 14:20   ` Lukas Wunner
2025-07-15  6:13     ` Christoph Hellwig
2025-07-15  6:35       ` dan.j.williams [this message]
2025-07-15  8:42         ` Lukas Wunner
2025-07-15 16:26           ` Bjorn Helgaas

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=6875f6b72057a_11344100f1@dwillia2-mobl4.notmuch \
    --to=dan.j.williams@intel.com \
    --cc=adrian.hunter@intel.com \
    --cc=alexander.usyskin@intel.com \
    --cc=alison.schofield@intel.com \
    --cc=axboe@kernel.dk \
    --cc=dave.jiang@intel.com \
    --cc=dave@stgolabs.net \
    --cc=decui@microsoft.com \
    --cc=djeffery@redhat.com \
    --cc=dmitry.torokhov@gmail.com \
    --cc=even.xu@intel.com \
    --cc=haiyangz@microsoft.com \
    --cc=hch@lst.de \
    --cc=helgaas@kernel.org \
    --cc=ira.weiny@intel.com \
    --cc=jallison@ciq.com \
    --cc=jdelvare@suse.com \
    --cc=jonathan.cameron@huawei.com \
    --cc=kbusch@kernel.org \
    --cc=koby.elbaz@intel.com \
    --cc=konstantin.sinyuk@intel.com \
    --cc=kys@microsoft.com \
    --cc=linux-pci@vger.kernel.org \
    --cc=lukas@wunner.de \
    --cc=sagi@grimberg.me \
    --cc=stern@rowland.harvard.edu \
    --cc=stuart.w.hayes@gmail.com \
    --cc=vishal.l.verma@intel.com \
    --cc=wei.liu@kernel.org \
    --cc=xinpeng.sun@intel.com \
    --cc=yaron.avizrat@intel.com \
    /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).