Re: [PATCH v4] counter: Add support for Intel Quadrature Encoder Peripheral

[Jarkko Nikula <jarkko.nikula@linux.intel.com>]

On 6/3/21 7:12 PM, Jonathan Cameron wrote:
> On Wed,  2 Jun 2021 14:32:59 +0300
> Jarkko Nikula <jarkko.nikula@linux.intel.com> wrote:
>> +static int intel_qep_suspend(struct device *dev)
>> +{
>> +	struct pci_dev *pdev = container_of(dev, struct pci_dev, dev);
> 
> to_pci_dev()
> Though if all you are doing is using it to then get the drvdata
> avoid the round trip.  There have been a few patch sets tidying this up
> in recent years and good not to add the noise of having that happen here.
> 
> struct intel_qep *qep = dev_get_drvdata(dev);
> 
Now I remember, I got this dev_get_drvdata() idea here earlier but 
implemented it first to another driver and Uwe had a good point about 
kind of layer violation of relying dev_get_drvdata() to return what 
pci_set_drvdata() set:

https://www.spinics.net/lists/linux-pwm/msg15325.html

Jarkko