From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Tri Vo <trong@android.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>,
Stephen Boyd <swboyd@chromium.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux PM <linux-pm@vger.kernel.org>,
Kalesh Singh <kaleshsingh@google.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Ravi Chandra Sadineni <ravisadineni@chromium.org>
Subject: Re: [PATCH] PM / wakeup: Avoid dev_name collisions in wakeup class
Date: Mon, 29 Jul 2019 11:06:58 +0200 [thread overview]
Message-ID: <1771170.ZfA44AmTq3@kreacher> (raw)
In-Reply-To: <CANA+-vDNkSG39SLd0_B_L8gkDkfQ2uJLcuvCaRgHkU8DiBzMTw@mail.gmail.com>
On Saturday, July 27, 2019 7:37:07 PM CEST Tri Vo wrote:
> On Sat, Jul 27, 2019 at 6:10 AM Rafael J. Wysocki <rafael@kernel.org> wrote:
> >
> > On Sat, Jul 27, 2019 at 3:11 AM Stephen Boyd <swboyd@chromium.org> wrote:
> > >
> > > If a device is wakeup capable and the driver calls device_wakeup_init()
> > > on it during probe and then userspace writes 'enabled' to that device's
> > > power/wakeup file in sysfs we'll try to create the same named wakeup
> > > device in sysfs. The kernel will complain about duplicate file names.
>
> Thanks for reporting the issue, Stephen!
> > >
> > > sysfs: cannot create duplicate filename '/devices/virtual/wakeup/1-1.1'
> > > kobject_add_internal failed for 1-1.1 with -EEXIST, don't try to register things with the same name in the same directory.
> > >
> > > It may be advantageous to not write 'enabled' to the wakeup file (see
> > > wakeup_store()) from userspace for these devices because we allocate
> > > devices and register them and then throw them all away later on if the
> > > device driver has already initialized the wakeup attribute. The
> > > implementation currently tries to avoid taking locks here so it seems
> > > best to optimize that path in a separate patch.
> > >
> > > Let's rename the wakeup class devices as 'wakeupN' with an IDA that's
> > > simple enough to just return some sort of number. In addition, let's
> > > make the device registering the wakeup the parent and include a 'name'
> > > attribute in case userspace wants to figure out the type of wakeup it is
> > > (in the case of virtual wakeups) or the device associated with the
> > > wakeup. This makes it easier for userspace to go from /sys/class/wakeup
> > > to a place in the device hierarchy where the wakeup is generated from
> > > like an input device.
> > >
> > > Cc: Tri Vo <trong@android.com>
> > > Cc: Kalesh Singh <kaleshsingh@google.com>
> > > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > > Cc: Ravi Chandra Sadineni <ravisadineni@chromium.org>
> > > Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> >
> > I'd rather change the commit that introduced this issue which is only
> > in linux-next for now.
>
> Raphael, could you roll back my patch? I'll work with Stephen to fix it.
I'll drop it, thanks!
next prev parent reply other threads:[~2019-07-29 9:07 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-27 1:10 [PATCH] PM / wakeup: Avoid dev_name collisions in wakeup class Stephen Boyd
2019-07-27 13:10 ` Rafael J. Wysocki
2019-07-27 17:37 ` Tri Vo
2019-07-29 9:06 ` Rafael J. Wysocki [this message]
2019-07-29 14:07 ` Stephen Boyd
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