linux-kernel - Re: [PATCH v2] PCI / PM: Avoid using device_may

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Date:   Fri, 30 Jun 2017 11:44:57 +0300
From:   Mika Westerberg <mika.westerberg@...ux.intel.com>
To:     "Rafael J. Wysocki" <rjw@...ysocki.net>
Cc:     linux-pci@...r.kernel.org, Bjorn Helgaas <helgaas@...nel.org>,
        Alan Stern <stern@...land.harvard.edu>,
        Kai-Heng Feng <kai.heng.feng@...onical.com>,
        Bjorn Helgaas <bhelgaas@...gle.com>,
        gregkh@...uxfoundation.org, USB list <linux-usb@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
        linux-pm@...r.kernel.org
Subject: Re: [PATCH v2] PCI / PM: Avoid using device_may_wakeup() for runtime
 PM

On Fri, Jun 30, 2017 at 12:37:00AM +0200, Rafael J. Wysocki wrote:
> On Friday, June 23, 2017 02:58:11 PM Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> > 
> > pci_target_state() calls device_may_wakeup() which checks whether
> > or not the device may wake up the system from sleep states, but
> > pci_target_state() is used for runtime PM too.
> > 
> > Since runtime PM is expected to always enable remote wakeup if
> > possible, modify pci_target_state() to take additional argument
> > indicating whether or not it should look for a state from which
> > the device can signal wakeup and pass either the return value
> > of device_can_wakeup(), or "false" (if the device itself is not
> > wakeup-capable) to it from the code related to runtime PM.
> > 
> > While at it, fix the comment in pci_dev_run_wake() which is not
> > about sleep states.
> > 
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> > ---
> > 
> > -> v2:
> > 
> > Passing "true" as the second argument to pci_target_state() for runtime PM
> > might trigger suboptimal state choices to be made, so pass the return value
> > of device_can_wakeup() to it instead and pass "false" to it in pci_dev_run_wake(),
> > because that assumes device_can_wakeup() to return "false" already.
> 
> This was sent a week ago without any response so far.
> 
> Any concerns?

No concerns from me.

Reviewed-by: Mika Westerberg <mika.westerberg@...ux.intel.com>