Hi Alan, > I have looked this over more carefully. It turns out that both of you > have misunderstood the purpose of CONFIG_USB_GADGET_DUALSPEED (and by > extension, CONFIG_USB_GADGET_SUPERSPEED). In fact, the existing > Kconfig file is also wrong. > > The _only_ reason for CONFIG_USB_GADGET_DUALSPEED is so that gadget > drivers can use conditional compilation to avoid including the > high-speed descriptors when the UDC doesn't support high-speed > operation. That's all. This means that the > CONFIG_USB_GAGDET_DUALSPEED option does not need to be > user-controllable in Kconfig. It should default to N, and UDC drivers > that support high speed should select it. > > The same should be true of CONFIG_USB_GADGET_HIGHSPEED. It should not > be user-controllable. It should default to N, and UDC drivers that > support SuperSpeed operation (after these patches, only dummy-hcd) > should select it. Ok, agreed. Thanks for the clarification. I saw your patch, I'll update mine in the same way. > There remains the other question, about whether composite_driver.speed > should be set to USB_SPEED_SUPER. I think the matter can be settled at > runtime. Iterate through all the function drivers; if all of them > support SuperSpeed and CONFIG_USB_GADGET_SUPERSPEED is enabled then set > composite_driver.speed to USB_SPEED_SUPER. Not sure how to verify this. I need to know whether the driver that is registered with the UDC is SS or not. This is before the function drivers are binded to it. So how can I verify at that point that the function drivers that will bind to this driver will provide SS descriptors? (I'm sorry, I don't have the ability to view the code at the moment and due to the time differences between us I don't want to leave this question for tomorrow and loose another day...) >Otherwise, if all of them > support high speed and CONFIG_USB_GADGET_DUALSPEED is enabled then set > composite_driver.speed to USB_SPEED_HIGH. Otherwise set it to > USB_SPEED_FULL. > > Alan Stern > Thanks, Tanya Brokhman -- Sent by an consultant of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum. -- 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
