From: Mika Westerberg <mika.westerberg@linux.intel.com>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: Alexander Fomichev <fomichev.ru@gmail.com>,
linux-pci@vger.kernel.org, linux@yadro.com,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
linux-pm@vger.kernel.org, Logan Gunthorpe <logang@deltatee.com>
Subject: Re: [PATCH RESEND] PCI: disable runtime PM for PLX switches
Date: Wed, 24 Apr 2019 17:58:19 +0300 [thread overview]
Message-ID: <20190424145819.GL2654@lahna.fi.intel.com> (raw)
In-Reply-To: <20190424141148.GA244134@google.com>
On Wed, Apr 24, 2019 at 09:11:48AM -0500, Bjorn Helgaas wrote:
> - Maybe the PCI sysfs accessors (pci_mmap_resource(), etc) should
> turn off runtime PM? If we allow mmap of a BAR and then put the
> device in D3hot, that seems like a bug that could affect lots of
> things. But maybe that's already done magically elsewhere?
IIRC there is no PM magic happening for MMIO userspace accesses.
What you suggest above sounds like a good way to fix it. We already do
similar for config space access from userspace (if the device is in
D3cold) so definitely makes sense to do the same for MMIO. However, I
don't think we need to disable runtime PM - it should be enough to
increase the reference count (pm_runtime_get_sync() and friends) during
the time the MMIO resource is mmapped.
next prev parent reply other threads:[~2019-04-24 14:58 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190415135903.wiyw34faiezdnbbs@yadro.com>
[not found] ` <20190415141554.GL126710@google.com>
2019-04-23 21:53 ` [PATCH RESEND] PCI: disable runtime PM for PLX switches Bjorn Helgaas
2019-04-24 10:01 ` Alexander Fomichev
2019-04-24 14:11 ` Bjorn Helgaas
2019-04-24 14:58 ` Mika Westerberg [this message]
2019-04-24 17:21 ` Bjorn Helgaas
2019-04-24 21:09 ` Rafael J. Wysocki
2019-06-27 11:06 ` Alexander Fomichev
2019-07-17 21:42 ` Bjorn Helgaas
2019-07-18 8:35 ` Rafael J. Wysocki
2019-04-24 16:01 ` Logan Gunthorpe
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=20190424145819.GL2654@lahna.fi.intel.com \
--to=mika.westerberg@linux.intel.com \
--cc=fomichev.ru@gmail.com \
--cc=helgaas@kernel.org \
--cc=linux-pci@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=linux@yadro.com \
--cc=logang@deltatee.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).