linux-usb.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Lukas Wunner <lukas@wunner.de>
To: Rajat Jain <rajatja@google.com>
Cc: linux-pci <linux-pci@vger.kernel.org>,
	Linux PM <linux-pm@vger.kernel.org>,
	linux-usb@vger.kernel.org, Bjorn Helgaas <bhelgaas@google.com>,
	Mika Westerberg <mika.westerberg@linux.intel.com>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Alex Levin <levinale@google.com>,
	Madhusudanarao Amara 
	<madhusudanarao.amara@intel.corp-partner.google.com>,
	Prashant Malani <pmalani@google.com>,
	"abhijeet.rao@intel.com" <abhijeet.rao@intel.com>
Subject: Re: PCIe device (thunderbolt tunneled) runtime suspended while driver wants to attach.
Date: Sat, 14 Aug 2021 08:41:42 +0200	[thread overview]
Message-ID: <20210814064142.GB25723@wunner.de> (raw)
In-Reply-To: <CACK8Z6HLr4tk4UkrzBN7wydDmqk=cqN2a7bQfVdjp9cE_ov_Jw@mail.gmail.com>

On Fri, Aug 13, 2021 at 10:26:06PM -0700, Rajat Jain wrote:
> 2) Is my understanding correct that any device should NOT be runtime
> suspended while a driver is trying to attach to the device? Where is
> this ensured (for e.g. for NVMEs)? Is this ensured by the driver core,
> or a device driver that is trying to probe a PCI device needs to
> ensure this?

For some reason the driver core only runtime resumes a device on unbind
(in __device_release_driver()), but not on bind (in driver_probe_device()).

However, the PCI core makes up for that by runtime resuming the device
in local_pci_probe().


> 3) So all downstream devices of a PCI bridge need to be suspended
> before it can be suspended (and vice versa for resume)? In other
> words, is ita bug if I notice that a PCI bridge is runtime suspended
> while any of its downstream devices are not?

Yes to both questions.


> 4) Any suggestions for me to try?

Could you try to bisect the issue?

Thanks,

Lukas

      reply	other threads:[~2021-08-14  6:51 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-14  5:26 PCIe device (thunderbolt tunneled) runtime suspended while driver wants to attach Rajat Jain
2021-08-14  6:41 ` Lukas Wunner [this message]

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=20210814064142.GB25723@wunner.de \
    --to=lukas@wunner.de \
    --cc=abhijeet.rao@intel.com \
    --cc=bhelgaas@google.com \
    --cc=levinale@google.com \
    --cc=linux-pci@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=madhusudanarao.amara@intel.corp-partner.google.com \
    --cc=mika.westerberg@linux.intel.com \
    --cc=pmalani@google.com \
    --cc=rajatja@google.com \
    --cc=rjw@rjwysocki.net \
    /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).