[3/7] usb: dwc3: pci: Store device properties dynamically

On Tue, Feb 20, 2018 at 11:12 PM, Thinh Nguyen
[off-list ref] wrote:

On 2/17/2018 7:29 AM, Andy Shevchenko wrote:

quoted

On Fri, Feb 16, 2018 at 11:55 PM, Thinh Nguyen
[off-list ref] wrote:

quoted

Add the ability to add device properties dynamically. Currently, device
properties are added to platform device using
platform_device_add_properties(). However, this function does not allow
adding properties incrementally. It is useful to have this ability when
the driver needs to set common device properties across different HW

I'm not sure it's useful anyhow.

quoted

or
if IP and FPGA validation test different configurations for different
HW.

Shouldn't be a separate stuff for FPGA exclusively?

Can you clarify/expand your question?

FPGA is the one which might have different properties at run time for
the same device.
So, why do we care on driver / generic level of it?

Shouldn't be FPGA manager take care of it (via DT overlays, for example)?

quoted

quoted

To address this issue, update dwc3_pci to store device properties to
an array and dynamically manage them here.

Introduce two new functions to do so:
  * dwc3_pci_add_one_property() - this function adds one property to
    dwc->properties array and increase its size as needed
  * dwc3_pci_add_properties() - this function takes a null terminated
    array of device properties and add them to dwc->properties

So, why you can't use ACPI / DT here?

dwc3_pci_add_properties() is a convenient function that takes statically
allocated array of (quirks) properties for different HW and store them
to dwc->properties. The idea is to add more properties on top of these
required quirks.

Yes, I understand that. What's wrong with DT? The built-in device
properties have the same nature as usual properties for DT.
Whenever driver calls device_property_read_uXX() or alike it would
check all property provides for asked one.

Other than that, quirks esp. for FPGA sounds so wrong. Why in the
first place not to make non-broken hardware?!