Re: [PATCH v2 00/10] usb: ulpi: remove "dev" field from struct ulpi_ops

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Aug 01, 2016 at 09:15:48PM +0300, Tal Shorer wrote:
> struct ulpi_ops is defined as follows:
> 
> struct ulpi_ops {
>         struct device *dev;
>         int (*read)(struct ulpi_ops *ops, u8 addr);
>         int (*write)(struct ulpi_ops *ops, u8 addr, u8 val);
> };
> 
> Upon calling ulpi_register_interface(), the struct device argument is
> put inside the struct ulpi_ops argument's dev field. Later, when
> calling the actual read()/write() operations, the struct ulpi_ops is
> passed to them and they use the stored device to access whatever
> private data they need.
> 
> This means that if one wishes to reuse the same oprations for multiple
> interfaces (e.g if we have multiple instances of the same controller),
> any but the last interface registered will not operate properly (and
> the one that does work will be at the mercy of the others to not mess
> it up).
> 
> I understand that barely any driver uses this bus right now, but I
> suppose it's there to be used at some point. We might as well fix the
> design here before we hit this bug.
> 
> This series fixes this by passing the given struct device directly to
> the operation functions via ulpi->dev.parent in ulpi_read() and
> ulpi_write(). It also changes the operations struct to be constant
> since now nobody has a reason to modify it.
> 
> Changes from v1:
>  * Split the actual api change into multiple patch as per Felipe Balbi's
>    suggestion. The series now first adds the new api, then migrates
>    everything to use and only then removes the old api.
> 
> Tal Shorer (10):
>   usb: ulpi: move setting of ulpi->dev parent up in ulpi_register()
>   usb: ulpi: add new api functions, {read|write}_dev()
>   usb: ulpi: use new api functions if available
>   usb: dwc3: ulpi: use new api
>   usb: ulpi: remove calls to old api callbacks
>   usb: ulpi: remove old api callbacks from struct ulpi_ops
>   usb: ulpi: rename operations {read|write}_dev to simply {read|write}
>   usb: ulpi: remove "dev" field from struct ulpi_ops
>   usb: ulpi: make ops struct constant
>   usb: dwc3: ulpi: make dwc3_ulpi_ops constant

I'd like to get Heikki's ack for this series...