From: "Rafael J. Wysocki" <rjw@sisk.pl>
To: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
Jesse Barnes <jbarnes@virtuousgeek.org>,
Yinghai Lu <yinghai@kernel.org>,
"Ronciak, John" <john.ronciak@intel.com>,
"Penner, Miles J" <miles.j.penner@intel.com>,
Bruce Allan <bruce.w.allan@intel.com>,
Heikki Krogerus <heikki.krogerus@linux.intel.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
"x86@kernel.org" <x86@kernel.org>
Subject: Re: [PATCH 1/6] PCI: acpiphp: do not check for SLOT_ENABLED in enable_device()
Date: Tue, 02 Jul 2013 22:49:50 +0200 [thread overview]
Message-ID: <2243397.l6uQhQpZPo@vostro.rjw.lan> (raw)
In-Reply-To: <20130702203117.GT9294@intel.com>
On Tuesday, July 02, 2013 11:31:17 PM Mika Westerberg wrote:
> On Tue, Jul 02, 2013 at 10:29:12PM +0200, Rafael J. Wysocki wrote:
> > On Tuesday, July 02, 2013 10:40:39 AM Bjorn Helgaas wrote:
> > > On Mon, Jul 1, 2013 at 7:29 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > > > On Monday, July 01, 2013 09:36:13 PM Mika Westerberg wrote:
> > > >> On Mon, Jul 01, 2013 at 04:01:37PM +0200, Rafael J. Wysocki wrote:
> > > >> > > Given the fact that SLOT_ENABLED is only checked in acpiphp_enable_slot()
> > > >> > > (after this patch) and that /sys/bus/pci/slots/*/power uses SLOT_POWEREDON
> > > >> > > anyway, should we remove the whole flag?
> > > >> >
> > > >> > Sure, if it is not necessary any more, we should remove it.
> > > >>
> > > >> Well, there is one thing that changes due that. Once the flag is gone
> > > >> userspace can do 'echo 1 > /sys/bus/pci/slots/*/power' several times and
> > > >> the slot is always re-enumerated.
> > > >>
> > > >> If that is not acceptable we should probably move the SLOT_ENABLED check
> > > >> closer to acpiphp_core:enable_device() and drop it from here, so that we
> > > >> always re-enumerate on Bus Check event but userspace can only do enable
> > > >> once (we still re-enumerate on Bus Check).
> > > >
> > > > Yes, that sounds like the right thing to do.
> > >
> > > Is it actually a problem if we re-enumerate every time userspace does
> > > 'echo 1 > /sys/bus/pci/slots/*/power'? I assume re-enumeration is a
> > > no-op if nothing has changed.
> >
> > Well, if it's a no-op in that case, then re-enumerating shouldn't be a problem,
> > but is it a no-op?
>
> I can confirm that it's a no-op (at least for the Thunderbolt case).
> Basically we just scan for new devices and nothing is to be found.
We can try to drop SLOT_ENABLED entirely then I suppose.
Thanks,
Rafael
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
next prev parent reply other threads:[~2013-07-02 20:40 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-25 16:22 [PATCH 0/6] Thunderbolt workarounds take 2 Mika Westerberg
2013-06-25 16:22 ` [PATCH 1/6] PCI: acpiphp: do not check for SLOT_ENABLED in enable_device() Mika Westerberg
2013-06-26 23:28 ` Bjorn Helgaas
2013-06-27 13:25 ` Kirill A. Shutemov
2013-06-28 9:51 ` Kirill A. Shutemov
2013-06-28 17:00 ` Bjorn Helgaas
2013-06-28 18:54 ` Rafael J. Wysocki
2013-07-01 9:32 ` Mika Westerberg
2013-07-01 14:01 ` Rafael J. Wysocki
2013-07-01 18:36 ` Mika Westerberg
2013-07-02 1:29 ` Rafael J. Wysocki
2013-07-02 16:40 ` Bjorn Helgaas
2013-07-02 20:29 ` Rafael J. Wysocki
2013-07-02 20:31 ` Mika Westerberg
2013-07-02 20:49 ` Rafael J. Wysocki [this message]
2013-06-25 16:22 ` [PATCH 2/6] PCI: acpiphp: enable_device(): rescan even if no new devices on slot Mika Westerberg
2013-06-26 23:37 ` Bjorn Helgaas
2013-06-27 13:02 ` Mika Westerberg
2013-06-27 16:32 ` Mika Westerberg
2013-06-27 16:50 ` Bjorn Helgaas
2013-06-27 16:54 ` Bjorn Helgaas
2013-06-27 1:20 ` Yinghai Lu
2013-06-27 13:04 ` Mika Westerberg
2013-06-25 16:22 ` [PATCH 3/6] PCI: introduce pci_trim_stale_devices() Mika Westerberg
2013-06-25 17:47 ` Andy Shevchenko
2013-06-25 17:56 ` Kirill A. Shutemov
2013-06-28 19:59 ` Rafael J. Wysocki
2013-06-25 16:22 ` [PATCH 4/6] PCI: acpiphp: check for new devices on enabled host Mika Westerberg
2013-06-25 18:04 ` Andy Shevchenko
2013-06-26 9:39 ` Kirill A. Shutemov
2013-06-27 19:05 ` Yinghai Lu
2013-06-28 9:33 ` Kirill A. Shutemov
2013-06-28 16:22 ` Yinghai Lu
2013-06-28 20:04 ` Rafael J. Wysocki
2013-06-25 16:22 ` [PATCH 5/6] PCI: acpiphp: look _RMV method a bit deeper in the hierarhcy Mika Westerberg
2013-06-25 18:15 ` Andy Shevchenko
2013-06-25 18:31 ` Mika Westerberg
2013-06-25 18:31 ` Andy Shevchenko
2013-06-25 18:51 ` Mika Westerberg
2013-06-25 19:30 ` Andy Shevchenko
2013-07-02 10:44 ` Kirill A. Shutemov
2013-07-02 17:09 ` Bjorn Helgaas
2013-07-02 17:45 ` Kirill A. Shutemov
2013-07-02 20:48 ` Rafael J. Wysocki
2013-07-02 20:40 ` Rafael J. Wysocki
2013-06-25 16:22 ` [PATCH 6/6] x86/PCI: quirk Thunderbolt PCI-to-PCI bridges Mika Westerberg
2013-06-25 21:15 ` Jesse Barnes
2013-06-26 12:17 ` Mika Westerberg
2013-06-26 15:04 ` Greg Kroah-Hartman
2013-06-26 20:59 ` Bjorn Helgaas
2013-06-26 22:15 ` Alex Williamson
2013-06-27 13:09 ` Mika Westerberg
2013-06-26 22:18 ` Bjorn Helgaas
2013-06-26 22:26 ` Yinghai Lu
2013-06-26 22:31 ` Yinghai Lu
2013-06-26 22:44 ` Rafael J. Wysocki
2013-06-26 22:38 ` Yinghai Lu
2013-06-26 22:55 ` Bjorn Helgaas
2013-06-26 23:56 ` Yinghai Lu
2013-06-27 16:00 ` Bjorn Helgaas
2013-06-27 17:27 ` Yinghai Lu
2013-06-27 13:58 ` Mika Westerberg
2013-06-27 13:54 ` Mika Westerberg
2013-06-27 16:27 ` Mika Westerberg
2013-06-27 17:18 ` Yinghai Lu
2013-06-25 23:24 ` [PATCH 0/6] Thunderbolt workarounds take 2 Rafael J. Wysocki
2013-06-26 7:25 ` Mika Westerberg
2013-06-26 12:45 ` Rafael J. Wysocki
2013-06-26 19:48 ` Bjorn Helgaas
2013-06-26 20:01 ` Rafael J. Wysocki
2013-06-26 19:55 ` Bjorn Helgaas
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