• Alan Stern's avatar
    [PATCH] USB UHCI: Detect invalid ports · e07fefa6
    Alan Stern authored
    This patch changes the way uhci-hcd detects valid ports.  The
    specification doesn't mention any way to find out how many ports a
    controller has, so the driver has to use some heuristics, reading the port
    status and control register and deciding whether the value makes sense.
    With this patch the driver will recognize a typical failure mode (all bits
    set to one) for nonexistent ports and won't assume there are always at
    least 2 ports -- such an assumption seems silly if the heuristics have
    already shown that the ports don't exist.
    Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
    e07fefa6
uhci-hcd.c 26.2 KB