• Jack Pham's avatar
    usb: dwc3: debugfs: Add and remove endpoint dirs dynamically · 8d396bb0
    Jack Pham authored
    The DWC3 DebugFS directory and files are currently created once
    during probe.  This includes creation of subdirectories for each
    of the gadget's endpoints.  This works fine for peripheral-only
    controllers, as dwc3_core_init_mode() calls dwc3_gadget_init()
    just prior to calling dwc3_debugfs_init().
    
    However, for dual-role controllers, dwc3_core_init_mode() will
    instead call dwc3_drd_init() which is problematic in a few ways.
    First, the initial state must be determined, then dwc3_set_mode()
    will have to schedule drd_work and by then dwc3_debugfs_init()
    could have already been invoked.  Even if the initial mode is
    peripheral, dwc3_gadget_init() happens after the DebugFS files
    are created, and worse so if the initial state is host and the
    controller switches to peripheral much later.  And secondly,
    even if the gadget endpoints' debug entries were successfully
    created, if the controller exits peripheral mode, its dwc3_eps
    are freed so the debug files would now hold stale references.
    
    So it is best if the DebugFS endpoint entries are created and
    removed dynamically at the same time the underlying dwc3_eps are.
    Do this by calling dwc3_debugfs_create_endpoint_dir() as each
    endpoint is created, and conversely remove the DebugFS entry when
    the endpoint is freed.
    
    Fixes: 41ce1456 ("usb: dwc3: core: make dwc3_set_mode() work properly")
    Cc: stable <stable@vger.kernel.org>
    Reviewed-by: default avatarPeter Chen <peter.chen@kernel.org>
    Signed-off-by: default avatarJack Pham <jackp@codeaurora.org>
    Link: https://lore.kernel.org/r/20210529192932.22912-1-jackp@codeaurora.orgSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    8d396bb0
debug.h 10.3 KB