At 2022-07-15 00:37:51, "Bjorn Helgaas" <helgaas@xxxxxxxxxx> wrote:
>On Mon, Jul 04, 2022 at 02:26:08PM +0800, Liang He wrote:
>> In ls_g4_pcie_probe(), we should hold the reference returned by
>> of_parse_phandle() and use it to call of_node_put() for refcount
>> balance.
>>
>> Fixes: d29ad70a813b ("PCI: mobiveil: Add PCIe Gen4 RC driver for Layerscape SoCs")
>> Co-authored-by: Miaoqian Lin <linmq006@xxxxxxxxx>
>> Signed-off-by: Liang He <windhl@xxxxxxx>
>> ---
>> drivers/pci/controller/mobiveil/pcie-layerscape-gen4.c | 6 ++++--
>> 1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/pci/controller/mobiveil/pcie-layerscape-gen4.c b/drivers/pci/controller/mobiveil/pcie-layerscape-gen4.c
>> index d7b7350f02dd..075aa487f92e 100644
>> --- a/drivers/pci/controller/mobiveil/pcie-layerscape-gen4.c
>> +++ b/drivers/pci/controller/mobiveil/pcie-layerscape-gen4.c
>> @@ -204,13 +204,15 @@ static int __init ls_g4_pcie_probe(struct platform_device *pdev)
>> struct pci_host_bridge *bridge;
>> struct mobiveil_pcie *mv_pci;
>> struct ls_g4_pcie *pcie;
>> - struct device_node *np = dev->of_node;
>> + struct device_node *np = dev->of_node, *parse_np;
>> int ret;
>>
>> - if (!of_parse_phandle(np, "msi-parent", 0)) {
>> + parse_np = of_parse_phandle(np, "msi-parent", 0);
>
>I don't understand what's going on here. Where is "msi-parent"
>actually used? If we just need to know whether "msi-parent" exists,
>can we use of_property_read_bool() instead? Or can we call
>of_parse_phandle() closer to where it is used?
>
Hi, Bjorn,
I think this code is used to check the existence of the device_node whose
property is "msi-parent". of_property_read_bool() can only be used to check
current device_node 'np'.
If this is right, I think we can use a helper to make thing simple like this:
https://lore.kernel.org/all/20220712061417.363145-1-windhl@xxxxxxx/
If it is ok, I will prepare the helper in new version.
Thanks again,
Liang
>> + if (!parse_np) {
>> dev_err(dev, "Failed to find msi-parent\n");
>> return -EINVAL;
>> }
>> + of_node_put(parse_np);
>>
>> bridge = devm_pci_alloc_host_bridge(dev, sizeof(*pcie));
>> if (!bridge)
>> --
>> 2.25.1
>>
