On Fri, Aug 14, 2015 at 04:08:10PM -0500, Rob Herring wrote:

On Fri, Aug 14, 2015 at 11:19 AM, Marc Zyngier [off-list ref] wrote:

quoted

Both pci-host-generic and Pseries parse the "linux,pci-probe-only"
to engage the PCI_PROBE_ONLY mode, and both have a subtle bug that
can be triggered if the property has no parameter.

Humm, I bet we could break a lot of machines if we fixed the core code
to properly make pp->value NULL when there is no value.

quoted

Provide a generic implementation that can be used by both.

Signed-off-by: Marc Zyngier <redacted>
---
 drivers/of/of_pci.c    | 30 ++++++++++++++++++++++++++++++
 include/linux/of_pci.h |  3 +++
 2 files changed, 33 insertions(+)

diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
index 5751dc5..a4e29ff 100644
--- a/drivers/of/of_pci.c
+++ b/drivers/of/of_pci.c

@@ -118,6 +118,36 @@ int of_get_pci_domain_nr(struct device_node *node)
 EXPORT_SYMBOL_GPL(of_get_pci_domain_nr);

 /**
+ * of_pci_check_probe_only - Setup probe only mode if linux,pci-probe-only
+ *                           is present and valid
+ *
+ * @node: device tree node that may contain the property (usually "chosen")
+ *
+ */
+void of_pci_check_probe_only(struct device_node *node)
+{
+       const int *prop;
+       int len;
+
+       if (!node)
+               return;
+
+       prop = of_get_property(node, "linux,pci-probe-only", &len);

It is preferred to use of_property_read_u32 to avoid just these types
of problems.

I don't know enough OF to really understand this, but I infer that
this is a suggestion for improving the patch.  Should I be waiting for
a v3 series?

Bjorn