From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Yinghai Lu <yinghai@kernel.org>, Bjorn Helgaas <bhelgaas@google.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>,
"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] Revert "PCI: Remove from bus_list and release resources in pci_release_dev()"
Date: Sat, 01 Feb 2014 15:38:29 +0100 [thread overview]
Message-ID: <14676899.LOmsodapl3@vostro.rjw.lan> (raw)
In-Reply-To: <CAE9FiQX_AuSPq159AwDHP+n0k6FK3pS2CNttPFAJP2K-84ho1w@mail.gmail.com>
On Friday, January 31, 2014 05:56:30 PM Yinghai Lu wrote:
> On Fri, Jan 31, 2014 at 3:34 PM, Rafael J. Wysocki <rjw@rjwysocki.net> wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
[...]
> > diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
> > index 4ff36bfa785e..b8c93c90daf5 100644
> > --- a/drivers/pci/remove.c
> > +++ b/drivers/pci/remove.c
> > @@ -3,6 +3,20 @@
> > #include <linux/pci-aspm.h>
> > #include "pci.h"
> >
> > +static void pci_free_resources(struct pci_dev *dev)
> > +{
> > + int i;
> > +
> > + msi_remove_pci_irq_vectors(dev);
>
> looks like you are in a rush. Why do you put back msi_remove_pci_irq_vectors?
I simply did "git revert" and that's the result.
Sorry about overlooking that, but your commit's changelog didn't mention
removing it either.
Updated revert follows.
Thanks,
Rafael
---
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Subject: Revert "PCI: Remove from bus_list and release resources in pci_release_dev()"
Revert commit ef83b0781a73 "PCI: Remove from bus_list and release
resources in pci_release_dev()" that made some nasty race conditions
become possible. For example, if a Thunderbolt link is unplugged
and then replugged immediately, the pci_release_dev() resulting from
the hot-remove code path may be racing with the hot-add code path
which after that commit causes various kinds of breakage to happen
(up to and including a hard crash of the whole system).
Moreover, the problem that commit ef83b0781a73 attempted to address
cannot happen any more after commit 8a4c5c329de7 "PCI: Check parent
kobject in pci_destroy_dev()", because pci_destroy_dev() will now
return immediately if it has already been executed for the given
device.
Note, however, that the invocation of msi_remove_pci_irq_vectors()
removed by commit ef83b0781a73 from pci_free_resources() along with
the other changes made by it is not added back because of subsequent
code changes depending on that modification.
Fixes: ef83b0781a73 (PCI: Remove from bus_list and release resources in pci_release_dev())
Reported-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
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---
drivers/pci/probe.c | 21 ++-------------------
drivers/pci/remove.c | 17 +++++++++++++++++
2 files changed, 19 insertions(+), 19 deletions(-)
Index: linux-pm/drivers/pci/probe.c
===================================================================
--- linux-pm.orig/drivers/pci/probe.c
+++ linux-pm/drivers/pci/probe.c
@@ -1208,18 +1208,6 @@ static void pci_release_capabilities(str
pci_free_cap_save_buffers(dev);
}
-static void pci_free_resources(struct pci_dev *dev)
-{
- int i;
-
- pci_cleanup_rom(dev);
- for (i = 0; i < PCI_NUM_RESOURCES; i++) {
- struct resource *res = dev->resource + i;
- if (res->parent)
- release_resource(res);
- }
-}
-
/**
* pci_release_dev - free a pci device structure when all users of it are finished.
* @dev: device that's been disconnected
@@ -1229,14 +1217,9 @@ static void pci_free_resources(struct pc
*/
static void pci_release_dev(struct device *dev)
{
- struct pci_dev *pci_dev = to_pci_dev(dev);
-
- down_write(&pci_bus_sem);
- list_del(&pci_dev->bus_list);
- up_write(&pci_bus_sem);
-
- pci_free_resources(pci_dev);
+ struct pci_dev *pci_dev;
+ pci_dev = to_pci_dev(dev);
pci_release_capabilities(pci_dev);
pci_release_of_node(pci_dev);
pcibios_release_device(pci_dev);
Index: linux-pm/drivers/pci/remove.c
===================================================================
--- linux-pm.orig/drivers/pci/remove.c
+++ linux-pm/drivers/pci/remove.c
@@ -3,6 +3,18 @@
#include <linux/pci-aspm.h>
#include "pci.h"
+static void pci_free_resources(struct pci_dev *dev)
+{
+ int i;
+
+ pci_cleanup_rom(dev);
+ for (i = 0; i < PCI_NUM_RESOURCES; i++) {
+ struct resource *res = dev->resource + i;
+ if (res->parent)
+ release_resource(res);
+ }
+}
+
static void pci_stop_dev(struct pci_dev *dev)
{
pci_pme_active(dev, false);
@@ -25,6 +37,11 @@ static void pci_destroy_dev(struct pci_d
device_del(&dev->dev);
+ down_write(&pci_bus_sem);
+ list_del(&dev->bus_list);
+ up_write(&pci_bus_sem);
+
+ pci_free_resources(dev);
put_device(&dev->dev);
}
next prev parent reply other threads:[~2014-02-01 14:24 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20140130131236.GW18029@intel.com>
2014-01-31 23:34 ` [PATCH] Revert "PCI: Remove from bus_list and release resources in pci_release_dev()" Rafael J. Wysocki
2014-02-01 1:56 ` Yinghai Lu
2014-02-01 14:38 ` Rafael J. Wysocki [this message]
2014-02-01 18:23 ` Linus Torvalds
2014-02-01 18:48 ` Mika Westerberg
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