• Alan Stern's avatar
    usb-storage: revert DMA-alignment change for Wireless USB · b0d87b93
    Alan Stern authored
    commit f756cbd4 upstream.
    
    This patch (as1110) reverts an earlier patch meant to help with
    Wireless USB host controllers.  These controllers can have bulk
    maxpacket values larger than 512, which puts unusual constraints on
    the sizes of scatter-gather list elements.  However it turns out that
    the block layer does not provide the support we need to enforce these
    constraints; merely changing the DMA alignment mask doesn't help.
    Hence there's no reason to keep the original patch.  The Wireless USB
    problem will have to be solved a different way.
    
    In addition, there is a reason to get rid of the earlier patch.  By
    dereferencing a pointer stored in the ep_in array of struct
    usb_device, the current code risks an invalid memory access when it
    runs concurrently with device removal.  The members of that array are
    cleared before the driver's disconnect method is called, so it should
    not try to use them.
    Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
    b0d87b93
scsiglue.c 16.3 KB