[PATCH] phy: amlogic: phy-meson-axg-mipi-pcie-analog: Hold reference returned by of_get_parent()

[Liang He]

At 2022-09-02 23:41:14, "Vinod Koul" <vkoul at kernel.org> wrote:
>On 05-07-22, 10:15, Liang He wrote:
>> We should hold the reference returned by of_get_parent() and use it
>> to call of_node_put() for reference balance.
>
>And why should we hold and drop reference?

>
Hi, Vinod Koul,


Thanks very much for your review.


As the of_get_parent() will increase the refcount of the node->parent  and the reference will be discarded 
so we should hold the reference , with which we can decrease the refcount.


If there is any misunderstanding about the of_get_parent() API, please correct me.


Thanks very much.


Liang

>> 
>> Fixes: 8eff8b4e22d9 ("phy: amlogic: phy-meson-axg-mipi-pcie-analog: add support for MIPI DSI analog")
>> Signed-off-by: Liang He <windhl at 126.com>
>> ---
>>  drivers/phy/amlogic/phy-meson-axg-mipi-pcie-analog.c | 6 ++++--
>>  1 file changed, 4 insertions(+), 2 deletions(-)
>> 
>> diff --git a/drivers/phy/amlogic/phy-meson-axg-mipi-pcie-analog.c b/drivers/phy/amlogic/phy-meson-axg-mipi-pcie-analog.c
>> index 1027ece6ca12..a3e1108b736d 100644
>> --- a/drivers/phy/amlogic/phy-meson-axg-mipi-pcie-analog.c
>> +++ b/drivers/phy/amlogic/phy-meson-axg-mipi-pcie-analog.c
>> @@ -197,7 +197,7 @@ static int phy_axg_mipi_pcie_analog_probe(struct platform_device *pdev)
>>  	struct phy_provider *phy;
>>  	struct device *dev = &pdev->dev;
>>  	struct phy_axg_mipi_pcie_analog_priv *priv;
>> -	struct device_node *np = dev->of_node;
>> +	struct device_node *np = dev->of_node, *parent_np;
>>  	struct regmap *map;
>>  	int ret;
>>  
>> @@ -206,7 +206,9 @@ static int phy_axg_mipi_pcie_analog_probe(struct platform_device *pdev)
>>  		return -ENOMEM;
>>  
>>  	/* Get the hhi system controller node */
>> -	map = syscon_node_to_regmap(of_get_parent(dev->of_node));
>> +	parent_np = of_get_parent(dev->of_node);
>> +	map = syscon_node_to_regmap(parent_np);
>> +	of_node_put(parent_np);
>>  	if (IS_ERR(map)) {
>>  		dev_err(dev,
>>  			"failed to get HHI regmap\n");
>> -- 
>> 2.25.1
>> 
>> 
>> -- 
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>> linux-phy at lists.infradead.org
>> https://lists.infradead.org/mailman/listinfo/linux-phy
>
>-- 
>~Vinod