Re: [PATCH v3 1/3] usb: typec: Separate USB Power Delivery from USB Type-C

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Wed, Apr 27, 2022 at 09:42:19AM +0300, Heikki Krogerus wrote:
> Hi,
> 
> On Tue, Apr 26, 2022 at 02:07:25PM +0200, Greg Kroah-Hartman wrote:
> > On Mon, Apr 25, 2022 at 03:49:44PM +0300, Heikki Krogerus wrote:
> > > --- /dev/null
> > > +++ b/drivers/usb/typec/pd.h
> > > @@ -0,0 +1,30 @@
> > > +/* SPDX-License-Identifier: GPL-2.0 */
> > > +
> > > +#ifndef __USB_POWER_DELIVERY__
> > > +#define __USB_POWER_DELIVERY__
> > > +
> > > +#include <linux/kobject.h>
> > 
> > Why kobject.h when:
> 
> Oops, that should now be "#include <linux/device.h>".
> 
> > > +
> > > +struct pd_capabilities {
> > > +	struct device dev;
> > 
> > This is a device?
> > 
> > > +	struct pd *pd;
> > > +	enum typec_role role;
> > > +};
> > > +
> > > +struct pd {
> > > +	struct device		dev;
> > > +	int			id;
> > > +
> > > +	u16			revision; /* 0300H = "3.0" */
> > 
> > So BCD?
> 
> Yes.
> 
> > > +	u16			version;
> > > +};
> > 
> > > +
> > > +#define to_pd_capabilities(o) container_of(o, struct pd_capabilities, dev)
> > > +#define to_pd(o) container_of(o, struct pd, dev)
> > > +
> > > +struct pd *pd_find(const char *name);
> > 
> > "struct pd" is just about the shortest structure name I've seen in the
> > kernel so far.  How about using some more letters?  :)
> 
> Okay, I'll make it usbpd.

How about some more vowels: "struct usb_power_delivery" please.  This
isn't the 1980's :)

> > > +
> > > +int pd_init(void);
> > > +void pd_exit(void);
> > 
> > The kobject question above goes to the code as well.  You are creating a
> > bunch of raw kobjects still, why?  This should all fit into the driver
> > model and kobjects shouldn't be needed.  Are you trying to nest too deep
> > in the attributes?  If so, kobjects will not work as userspace tools
> > will not realize they are there and are attributes at all.
> 
> They are not raw kobjects, they are all devices now. That header just
> needs to be fixed.

You have loads of kobject attributes in the .c file.  Either I read it
wrong, or you are doing something wrong, as that should never be the
case for a driver or device.

thanks,

greg k-h