* [Please ignore this is a test] pci-hyperv: properly handle pci bus remove
@ 2017-03-23 18:37 Long Li
2017-03-26 10:36 ` kbuild test robot
0 siblings, 1 reply; 2+ messages in thread
From: Long Li @ 2017-03-23 18:37 UTC (permalink / raw)
To: linux-pci, devel; +Cc: Long Li
From: Long Li <longli@microsoft.com>
hv_pci_devices_present is called in hv_pci_remove when we remove a PCI
device from host (e.g. by disabling SRIOV on a device). In hv_pci_remove,
the bus is already removed before the call, so we don't need to rescan the
bus in the workqueue scheduled from hv_pci_devices_present.
By introducing status hv_pcibus_removed, we can avoid this situation.
Signed-off-by: Long Li <longli@microsoft.com>
---
drivers/pci/host/pci-hyperv.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index ada9856..8a92244 100644
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -350,6 +350,7 @@ enum hv_pcibus_state {
hv_pcibus_init = 0,
hv_pcibus_probed,
hv_pcibus_installed,
+ hv_pcibus_removed,
hv_pcibus_maximum
};
@@ -1504,12 +1505,19 @@ static void pci_devices_present_work(struct work_struct *work)
put_pcichild(hpdev, hv_pcidev_ref_initial);
}
- /* Tell the core to rescan bus because there may have been changes. */
- if (hbus->state == hv_pcibus_installed) {
+ switch(hbus->state) {
+ case hv_pcibus_installed:
+ /*
+ * Tell the core to rescan bus
+ * because there may have been changes.
+ */
pci_lock_rescan_remove();
pci_scan_child_bus(hbus->pci_bus);
pci_unlock_rescan_remove();
- } else {
+ break;
+
+ case hv_pcibus_init:
+ case hv_pcibus_probed:
survey_child_resources(hbus);
}
@@ -2185,6 +2193,7 @@ static int hv_pci_probe(struct hv_device *hdev,
hbus = kzalloc(sizeof(*hbus), GFP_KERNEL);
if (!hbus)
return -ENOMEM;
+ hbus->state = hv_pcibus_init;
/*
* The PCI bus "domain" is what is called "segment" in ACPI and
@@ -2348,6 +2357,7 @@ static int hv_pci_remove(struct hv_device *hdev)
pci_stop_root_bus(hbus->pci_bus);
pci_remove_root_bus(hbus->pci_bus);
pci_unlock_rescan_remove();
+ hbus->state = hv_pcibus_removed;
}
hv_pci_bus_exit(hdev);
--
2.7.4
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [Please ignore this is a test] pci-hyperv: properly handle pci bus remove
2017-03-23 18:37 [Please ignore this is a test] pci-hyperv: properly handle pci bus remove Long Li
@ 2017-03-26 10:36 ` kbuild test robot
0 siblings, 0 replies; 2+ messages in thread
From: kbuild test robot @ 2017-03-26 10:36 UTC (permalink / raw)
To: Long Li; +Cc: kbuild-all, linux-pci, devel, Long Li
[-- Attachment #1: Type: text/plain, Size: 2057 bytes --]
Hi Long,
[auto build test WARNING on pci/next]
[also build test WARNING on v4.11-rc3 next-20170324]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Long-Li/pci-hyperv-properly-handle-pci-bus-remove/20170326-180444
base: https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git next
config: x86_64-randconfig-x016-201713 (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64
All warnings (new ones prefixed by >>):
drivers/pci/host/pci-hyperv.c: In function 'pci_devices_present_work':
>> drivers/pci/host/pci-hyperv.c:1508:2: warning: enumeration value 'hv_pcibus_removed' not handled in switch [-Wswitch]
switch(hbus->state) {
^~~~~~
>> drivers/pci/host/pci-hyperv.c:1508:2: warning: enumeration value 'hv_pcibus_maximum' not handled in switch [-Wswitch]
vim +/hv_pcibus_removed +1508 drivers/pci/host/pci-hyperv.c
1492 put_pcichild(hpdev, hv_pcidev_ref_childlist);
1493 list_move_tail(&hpdev->list_entry, &removed);
1494 break;
1495 }
1496 }
1497 } while (found);
1498 spin_unlock_irqrestore(&hbus->device_list_lock, flags);
1499
1500 /* Delete everything that should no longer exist. */
1501 while (!list_empty(&removed)) {
1502 hpdev = list_first_entry(&removed, struct hv_pci_dev,
1503 list_entry);
1504 list_del(&hpdev->list_entry);
1505 put_pcichild(hpdev, hv_pcidev_ref_initial);
1506 }
1507
> 1508 switch(hbus->state) {
1509 case hv_pcibus_installed:
1510 /*
1511 * Tell the core to rescan bus
1512 * because there may have been changes.
1513 */
1514 pci_lock_rescan_remove();
1515 pci_scan_child_bus(hbus->pci_bus);
1516 pci_unlock_rescan_remove();
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 28391 bytes --]
^ permalink raw reply [flat|nested] 2+ messages in thread
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