* [PATCH 1/2 v5] pci-hyperv: properly handle pci bus remove
@ 2017-03-23 21:58 Long Li
2017-03-24 14:55 ` Bjorn Helgaas
0 siblings, 1 reply; 2+ messages in thread
From: Long Li @ 2017-03-23 21:58 UTC (permalink / raw)
To: K. Y. Srinivasan, Haiyang Zhang, Bjorn Helgaas,
Stephen Hemminger, devel, linux-pci, linux-kernel
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>
Reported-by: Xiaofeng Wang <xiaofwan@redhat.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
---
drivers/pci/host/pci-hyperv.c | 20 +++++++++++++++++---
1 file changed, 17 insertions(+), 3 deletions(-)
diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index ada9856..39fafda 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
};
@@ -1504,13 +1505,24 @@ 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);
+ break;
+
+ default:
+ break;
}
up(&hbus->enum_sem);
@@ -2185,6 +2197,7 @@ 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 +2361,7 @@ 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: [PATCH 1/2 v5] pci-hyperv: properly handle pci bus remove
2017-03-23 21:58 [PATCH 1/2 v5] pci-hyperv: properly handle pci bus remove Long Li
@ 2017-03-24 14:55 ` Bjorn Helgaas
0 siblings, 0 replies; 2+ messages in thread
From: Bjorn Helgaas @ 2017-03-24 14:55 UTC (permalink / raw)
To: Long Li
Cc: K. Y. Srinivasan, Haiyang Zhang, Bjorn Helgaas,
Stephen Hemminger, devel, linux-pci, linux-kernel, Long Li
On Thu, Mar 23, 2017 at 02:58:10PM -0700, Long Li wrote:
> 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>
> Reported-by: Xiaofeng Wang <xiaofwan@redhat.com>
> Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Applied both patches to pci/host-hv for v4.12, thanks! They both applied
perfectly :)
> ---
> drivers/pci/host/pci-hyperv.c | 20 +++++++++++++++++---
> 1 file changed, 17 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
> index ada9856..39fafda 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
> };
>
> @@ -1504,13 +1505,24 @@ 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);
> + break;
> +
> + default:
> + break;
> }
>
> up(&hbus->enum_sem);
> @@ -2185,6 +2197,7 @@ 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 +2361,7 @@ 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 [flat|nested] 2+ messages in thread
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