Re: [PATCH] NFC: NCI: make parent aware in PM terms

On 19.08.21 16:45, Krzysztof Kozlowski wrote
Hi,
> Hi,
>
> Thanks for the patch.
> However this
> is unparseable.
> Please wrap commit
> message around 75th character:
> https://elixir.bootlin.com/linux/v5.13/source/Documentation/process/submitting-patches.rst#L124
>
> The subject prefix: "nfc: nxp-nci: "
OK.
> Please also Cc all people and lists. You missed here netdev
> and linux-kernel, so this cannot be applied.
Do you really want LKML on CC for all NFC patches?
>> The necessary extension of runtime PM
>> to the NFC device requires that it
>> be activated as a child of the i2c device.
>> It is not necessary to do any runtime PM
>> operations. This will disable runtime PM
>> for this branch of the tree, but otherwise
>> the NFC device is inoperable.
>>
>> Signed-off-by: Oliver Neukum <[email protected]>
>> ---
>>  drivers/nfc/nxp-nci/i2c.c | 10 ++++++++++
>>  1 file changed, 10 insertions(+)
>>
>> diff --git a/drivers/nfc/nxp-nci/i2c.c b/drivers/nfc/nxp-nci/i2c.c
>> index 94f7f6d9cbad..dba78a5d217a 100644
>> --- a/drivers/nfc/nxp-nci/i2c.c
>> +++ b/drivers/nfc/nxp-nci/i2c.c
>> @@ -18,6 +18,7 @@
>>  #include <linux/interrupt.h>
>>  #include <linux/module.h>
>>  #include <linux/nfc.h>
>> +#include <linux/pm_runtime.h>
>>  #include <linux/gpio/consumer.h>
>>  #include <asm/unaligned.h>
>>  
>> @@ -261,6 +262,7 @@ static int nxp_nci_i2c_probe(struct i2c_client *client,
>>  {
>>  	struct device *dev = &client->dev;
>>  	struct nxp_nci_i2c_phy *phy;
>> +	struct nfc_dev *ndev;
>>  	int r;
>>  
>>  	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
>> @@ -297,6 +299,11 @@ static int nxp_nci_i2c_probe(struct i2c_client *client,
>>  	if (r < 0)
>>  		return r;
>>  
>> +	ndev = phy->ndev->nfc_dev;
>> +	pm_runtime_set_active(&ndev->dev);
>> +	pm_runtime_enable(&ndev->dev);
>> +	pm_runtime_mark_last_busy(&ndev->dev);
> Setting PM for someone else does not look correct. This breaks
As far as I can tell I am doing this for the device noted in nfc_dev.
Could you elaborate?
> encapsulation and separation of these files. The NCI device
> (nxp_nci_probe() and other parts of core.c) should instead manage
> it's own runtime PM.

That would be better. The problem I encountered is that i2c and USB have
different
needs concerning runtime PM. Any ideas?

    Regards
        Oliver