This patch series adds support for delegation of GET_DESCRIPTOR requests from GadgetFS to user mode driver. This will allow deeper testing of USB hosts using GadgetFS, since it allows a user mode driver to control the responses to to GET_DESCRIPTOR requests, and respond with malformed descriptors.
Enabling this feature will break compatibility, since GadgetFS will not handle GET_DESCRIPTOR requests, although every user-mode driver so far expects it to. So we add three protection mechanisms to avoid this: - enabling this feature will only be possible by enabling USB_GADGETFS_ALLOW_DELEGATE_DESCRIPTOR in Kconfig, which depends enabling EXPERT as well. - even when enabled in Kconfig, delegation will be disabled until an appropriate ioctl on the control endpoint file descriptor is issued. - enabling this feature is done per file descriptor. if a user enables this feature and then close and re-open the control endpoint file, the feature will be disabled until the ioctl will be issued on the new file descriptor. -- Binyamin Sharet, Cisco, STARE-C -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
