From: "Rafael J. Wysocki" <rafael@kernel.org>
To: "吳昊澄 Ricky" <ricky_wu@realtek.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>,
Bjorn Helgaas <helgaas@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Ulf Hansson <ulf.hansson@linaro.org>,
Bjorn Helgaas <bhelgaas@google.com>,
"vaibhavgupta40@gmail.com" <vaibhavgupta40@gmail.com>,
"kdlnx@doth.eu" <kdlnx@doth.eu>,
Doug Anderson <dianders@chromium.org>,
"rmfrfs@gmail.com" <rmfrfs@gmail.com>,
Lee Jones <lee.jones@linaro.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-mmc <linux-mmc@vger.kernel.org>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Linux PM <linux-pm@vger.kernel.org>
Subject: Re: [PATCH] misc: rtsx: rts5249 support runtime PM
Date: Thu, 26 Nov 2020 15:19:26 +0100 [thread overview]
Message-ID: <CAJZ5v0ggtd3+YEo2nERhuTeurRx5OQrvLkAz3aEMPRmEfo_Rnw@mail.gmail.com> (raw)
In-Reply-To: <6f721ea4d5a84f45b0249b932d742367@realtek.com>
On Thu, Nov 26, 2020 at 4:07 AM 吳昊澄 Ricky <ricky_wu@realtek.com> wrote:
>
> > -----Original Message-----
> > From: Rafael J. Wysocki [mailto:rafael@kernel.org]
> > Sent: Wednesday, November 25, 2020 10:04 PM
> > To: Bjorn Helgaas; 吳昊澄 Ricky
[cut]
> > > > +static void rtsx_pci_rtd3_work(struct work_struct *work)
> > > > +{
> > > > + struct delayed_work *dwork = to_delayed_work(work);
> > > > + struct rtsx_pcr *pcr = container_of(dwork, struct rtsx_pcr,
> > rtd3_work);
> > > > +
> > > > + pcr_dbg(pcr, "--> %s\n", __func__);
> > > > +
> > > > + while (pcr->pci->dev.power.usage_count.counter > 0) {
> > > > + if (pm_runtime_active(&(pcr->pci->dev)))
> > > > + pm_runtime_put(&(pcr->pci->dev));
> > >
> > > I'm not a runtime PM expert, but this looks fishy. AFAICT this is the
> > > only driver in the tree that uses usage_count.counter this way, which
> > > is a pretty big hint that this needs a closer look. Cc'd Rafael.
> >
> > You are right, this is not correct from the PM-runtime POV.
> >
> > It looks like this attempts to force the PM-runtime usage counter down
> > to 0 and it's kind of hard to say why this is done (and it shouldn't
> > be done in the first place, because it destroys the usage counter
> > balance).
> >
> > Ricky, is this an attempt to work around an issue of some sort?
> >
>
> Thanks Bjorn and Rafael
> I found when we boot up, our dev pcr->pci->dev.power.usage_count.counter always is 2,
> Don’t know how to make it to 0 because we need to support D3 and run runtime_suspended callback function
> Is there something wrong with us to enable runtime PM?
That is possible.
If you want it to be enabled by default, you need to call
pm_runtime_allow() from the driver at probe time, in addition to
pm_runtime_enable(), in the first place, but that only drops one
reference, so question is where the other one comes from.
Are the pm_runtime_get*() and pm_runtime_put*() calls balanced?
next prev parent reply other threads:[~2020-11-26 14:19 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-24 6:02 [PATCH] misc: rtsx: rts5249 support runtime PM ricky_wu
2020-11-24 20:49 ` Bjorn Helgaas
2020-11-25 14:04 ` Rafael J. Wysocki
2020-11-26 3:07 ` 吳昊澄 Ricky
2020-11-26 14:19 ` Rafael J. Wysocki [this message]
2020-11-26 15:02 ` Ulf Hansson
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=CAJZ5v0ggtd3+YEo2nERhuTeurRx5OQrvLkAz3aEMPRmEfo_Rnw@mail.gmail.com \
--to=rafael@kernel.org \
--cc=arnd@arndb.de \
--cc=bhelgaas@google.com \
--cc=dianders@chromium.org \
--cc=gregkh@linuxfoundation.org \
--cc=helgaas@kernel.org \
--cc=kdlnx@doth.eu \
--cc=lee.jones@linaro.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mmc@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=ricky_wu@realtek.com \
--cc=rjw@rjwysocki.net \
--cc=rmfrfs@gmail.com \
--cc=ulf.hansson@linaro.org \
--cc=vaibhavgupta40@gmail.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).