On Wed, Jun 29, 2016 at 4:00 PM, Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx> wrote: > On Wed, Jun 29, 2016 at 02:21:10PM +0530, Rajaram R wrote: >> On Mon, Jun 27, 2016 at 5:43 PM, Heikki Krogerus >> <heikki.krogerus@xxxxxxxxxxxxxxx> wrote: >> > Hi, >> > >> > On Mon, Jun 27, 2016 at 03:51:08PM +0530, Rajaram R wrote: >> >> May be I am missing user or usage of the driver.. I see this driver is >> >> providing limited information of the Type-C connectors or the port >> >> partner >> > >> > Yes, this interface can't provide directly information received from >> > PD commands like Discover Identity. We will have to present the >> > partners even when USB PD is not supported and in a consistent >> > fashion. Some details will be available in any case indirectly. Like >> > if there are modes, there will be devices presenting them, and the >> > product type in case of partners will be the partner type. >> >> Agree. What is the end use of this driver? IMO end use case will >> decide what attributes to be shared. Since we are terming this as a >> universal representation for user space we may need to expose details >> such as Discovery details say Vendor ID, Product ID, Super Speed >> support etc which are not related to alt mode. In the legacy drivers >> complete descriptors of the device is available for user space to >> build applications. > > The details about the USB connection are out side the scope the this > class, and in most cases the port driver will not even have them at > their disposal. We can determine that the connector is in USB mode, > and that's about it. > > But those details will in any case be exposed by the USB subsystem, so > why should we duplicate them? The user space has been so far relying > on getting the details from the normal interfaces the USB subsystem > provides and that should not change. Apologize for bringing in USB example. I used it to as an example to say that complete device details are exposed to user space by other drivers. Sticking to the current topic/context more details of Type-C port/partner, a detailed information(with restrictions) will help build more user applications. > > > Thanks, > > -- > heikki -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
