From: Eran Liberty <liberty@extricom.com>
To: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>, eran.liberty@gmail.com
Subject: [PATCH 2.6.26] PCI: refuse to re-add a device to a bus upon pci_scan_child_bus()
Date: Mon, 21 Jul 2008 22:18:19 +0300 [thread overview]
Message-ID: <4884E0FB.9010909@extricom.com> (raw)
In-Reply-To: <48591941.4070408@extricom.com>
[-- Attachment #1: Type: text/plain, Size: 1150 bytes --]
Dear Penguins,
As a follow up on my own post ( http://lkml.org/lkml/2008/6/18/195 ), I
have solved a small bug/misbehavior within the pci_scan_single_device().
The misbehavior manifest itself upon calling pci_scan_child_bus() with a
bus which already contain some devices. After scanning is done devices
that already existed will be present twice in the PCI bus devise list.
Once with is_added indication and once without. Trying to add this bus
will cause a resource conflict as the same device is already present and
initialized.
This patch will simply prevent a device to be added to a pci bus list if
it is already there.
Points to consider:
1. I am not a PCI Guru and might have over looked the bigger picture. Is
it OK to prevent a device of being re-added?
2. I have decided that two devices are, in fact, the same instance if it
has the same: vendor, device, and devfn. Is there a finer test for a
device identity?
p.s. As per http://www.kernel.org/pub/linux/docs/lkml/#s1-10 it is
preferred for Mozilla Firefox clients to attach the patch, hence my
patch is attached.
Liberty
Signed-off-by: Eran Liberty <liberty@extricom.org>
---
[-- Attachment #2: refuse_readd_pci_device.patch --]
[-- Type: text/x-patch, Size: 794 bytes --]
drivers/pci/probe.c | 10 ++++++++++
1 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index b1724cf..e3c3ee0 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1002,11 +1002,21 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
struct pci_dev *__ref pci_scan_single_device(struct pci_bus *bus, int devfn)
{
struct pci_dev *dev;
+ struct list_head *ln;
dev = pci_scan_device(bus, devfn);
if (!dev)
return NULL;
+ /* refuse to re-add a device */
+ list_for_each(ln, &bus->devices) {
+ struct pci_dev *d = pci_dev_b(ln);
+ if ((d->vendor == dev->vendor) &&
+ (d->device == dev->device) &&
+ (d->devfn == dev->devfn))
+ return NULL;
+ }
+
pci_device_add(dev, bus);
return dev;
next prev parent reply other threads:[~2008-07-21 19:21 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-06-18 14:18 2.6.24-rc4: pci_remove_bus_device() => pci_scan_child_bus() => pci_bus_add_devices bug? Eran Liberty
2008-07-20 10:31 ` [PATCH 2.6.24-rc4] PCI: refuse to re-add a device to a bus upon pci_scan_child_bus() Eran Liberty
2008-07-20 16:48 ` Eran Liberty
2008-07-21 19:18 ` Eran Liberty [this message]
2008-07-21 19:49 ` [PATCH 2.6.26] " Matthew Wilcox
2008-07-22 8:21 ` eran liberty
2008-07-22 11:49 ` Matthew Wilcox
2008-07-22 13:08 ` Eran Liberty
2008-07-22 13:14 ` Eran Liberty
2008-07-22 14:13 ` Matthew Wilcox
2008-07-22 15:25 ` Eran Liberty
2008-07-22 16:52 ` Matthew Wilcox
2008-07-22 17:41 ` Eran Liberty
2008-07-22 18:11 ` Matthew Wilcox
2008-07-23 18:31 ` Eran Liberty
2008-07-27 11:01 ` Eran Liberty
2008-07-27 15:08 ` Matthew Wilcox
2008-08-18 8:08 ` ftrace introduces instability into kernel 2.6.27(-rc2,-rc3) Eran Liberty
2008-08-18 15:07 ` Steven Rostedt
2008-08-18 15:47 ` Mathieu Desnoyers
2008-08-18 16:12 ` Steven Rostedt
2008-08-18 17:04 ` Mathieu Desnoyers
2008-08-18 17:21 ` Scott Wood
2008-08-18 18:27 ` Steven Rostedt
2008-08-18 18:29 ` Scott Wood
2008-08-19 1:53 ` Benjamin Herrenschmidt
2008-08-19 2:28 ` Steven Rostedt
2008-08-19 2:39 ` Benjamin Herrenschmidt
2008-08-19 2:41 ` Steven Rostedt
2008-08-19 2:47 ` Mathieu Desnoyers
2008-08-19 3:32 ` Steven Rostedt
2008-08-19 3:36 ` Mathieu Desnoyers
2008-08-19 4:00 ` Steven Rostedt
2008-08-19 16:47 ` Steven Rostedt
2008-08-19 17:34 ` Mathieu Desnoyers
2008-08-19 21:08 ` Steven Rostedt
2008-08-20 9:40 ` Nick Piggin
2008-08-19 21:47 ` Benjamin Herrenschmidt
2008-08-19 23:58 ` Jeremy Fitzhardinge
2008-08-20 1:17 ` Benjamin Herrenschmidt
2008-08-19 2:56 ` Benjamin Herrenschmidt
2008-08-19 3:12 ` Steven Rostedt
2008-08-19 4:17 ` Benjamin Herrenschmidt
2008-08-20 7:18 ` Benjamin Herrenschmidt
2008-08-20 13:14 ` Steven Rostedt
2008-08-20 13:19 ` Steven Rostedt
2008-08-20 13:36 ` Eran Liberty
2008-08-20 13:43 ` Steven Rostedt
2008-08-20 14:02 ` Eran Liberty
2008-08-20 14:55 ` Jon Smirl
2008-08-20 15:23 ` Steven Rostedt
2008-08-20 18:23 ` Eran Liberty
2008-08-20 18:33 ` Steven Rostedt
2008-08-20 15:27 ` Steven Rostedt
2008-08-20 21:37 ` Benjamin Herrenschmidt
2008-08-20 14:16 ` Josh Boyer
2008-08-20 14:22 ` Steven Rostedt
2008-08-20 14:50 ` Josh Boyer
2008-09-15 16:30 ` [PATCH 2.6.26] SERIAL DRIVER: Handle Multiple consecutive sysrq from the serial Eran Liberty
2008-09-17 23:46 ` Andrew Morton
2008-09-18 6:58 ` Eran Liberty
2008-08-20 21:36 ` ftrace introduces instability into kernel 2.6.27(-rc2,-rc3) Benjamin Herrenschmidt
2008-08-20 21:44 ` Steven Rostedt
2008-08-18 18:47 ` Steven Rostedt
2008-08-18 18:56 ` Scott Wood
2008-08-18 19:28 ` Steven Rostedt
2008-08-18 18:25 ` Eran Liberty
2008-08-18 18:41 ` Mathieu Desnoyers
2008-08-19 1:54 ` Benjamin Herrenschmidt
2008-08-19 9:56 ` Eran Liberty
2008-08-19 13:02 ` Mathieu Desnoyers
2008-08-19 21:46 ` Benjamin Herrenschmidt
2008-08-18 18:50 ` Steven Rostedt
2008-08-19 12:09 ` Eran Liberty
2008-08-19 13:05 ` Mathieu Desnoyers
2008-08-19 14:21 ` Eran Liberty
2008-08-19 14:42 ` Mathieu Desnoyers
2008-08-19 20:15 ` Steven Rostedt
2008-08-20 11:18 ` Eran Liberty
2008-08-20 13:12 ` Steven Rostedt
2008-08-19 1:51 ` Benjamin Herrenschmidt
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