Hi Heikki,
On 1/25/22 4:18 AM, Heikki Krogerus wrote:
> On Mon, Jan 24, 2022 at 12:33:44PM -0500, Sean Anderson wrote:
>> of_node_put should always be called on device nodes gotten from
>> of_get_*. Additionally, it should only be called after there are no
>> remaining users. To address the first issue, call of_node_put if later
>> steps in ulpi_register fail. To address the latter, call of_node_put
>> only after calling device_unregister.
>
> This looks like a fix, but you don't have the fix tag.
You're right this should have
Fixes: ef6a7bcfb01c ("usb: ulpi: Support device discovery via DT")
>> Signed-off-by: Sean Anderson <sean.anderson@xxxxxxxx>
>> ---
>>
>> Changes in v2:
>> - New
>>
>> drivers/usb/common/ulpi.c | 10 +++++++---
>> 1 file changed, 7 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/usb/common/ulpi.c b/drivers/usb/common/ulpi.c
>> index 87deb514eb78..c6ba72544f2b 100644
>> --- a/drivers/usb/common/ulpi.c
>> +++ b/drivers/usb/common/ulpi.c
>> @@ -301,11 +301,11 @@ static int ulpi_register(struct device *dev, struct ulpi *ulpi)
>>
>> ret = ulpi_read_id(ulpi);
>> if (ret)
>> - return ret;
>> + goto err;
>>
>> ret = device_register(&ulpi->dev);
>> if (ret)
>> - return ret;
>> + goto err;
>
> I think there is another bug in the code here. Missing put_device().
So what is the correct way to create a device? Shouldn't device_register
be paired with device_unregister? And from what I can tell,
device_unregister does not put the of_node.
> If you first fix that, you should then be able to call
> fwnode_handle_put() (instead of of_node_put())
Well, we currently only have a ulpi_of_register, so I don't think we
will have a fwnode here. But I can use that if you wish.
--Sean
> from
> ulpi_dev_release(), and that should cover all cases.
>
>> root = debugfs_create_dir(dev_name(dev), ULPI_ROOT);
>> debugfs_create_file("regs", 0444, root, ulpi, &ulpi_regs_ops);
>> @@ -314,6 +314,10 @@ static int ulpi_register(struct device *dev, struct ulpi *ulpi)
>> ulpi->id.vendor, ulpi->id.product);
>>
>> return 0;
>> +
>> +err:
>> + of_node_put(ulpi->dev.of_node);
>> + return ret;
>
> So no need for that.
>
>> }
>>
>> /**
>> @@ -357,8 +361,8 @@ void ulpi_unregister_interface(struct ulpi *ulpi)
>> {
>> debugfs_remove_recursive(debugfs_lookup(dev_name(&ulpi->dev),
>> ULPI_ROOT));
>> - of_node_put(ulpi->dev.of_node);
>> device_unregister(&ulpi->dev);
>> + of_node_put(ulpi->dev.of_node);
>> }
>
> And here you can just remove that of_node_put() call.
>
> thanks,
>
