• G
    usb: host: xhci: Enable XHCI_SPURIOUS_SUCCESS for all controllers with xhci 1.0 · 07f3cb7c
    George Cherian 提交于
    Xhci controllers with hci_version > 0.96 gives spurious success
    events on short packet completion. During webcam capture the
    "ERROR Transfer event TRB DMA ptr not part of current TD" was observed.
    The same application works fine with synopsis controllers hci_version 0.96.
    The same issue is seen with Intel Pantherpoint xhci controller. So enabling
    this quirk in xhci_gen_setup if controller verion is greater than 0.96.
    For xhci-pci move the quirk to much generic place xhci_gen_setup.
    
    Note from Sarah:
    
    The xHCI 1.0 spec changed how hardware handles short packets.  The HW
    will notify SW of the TRB where the short packet occurred, and it will
    also give a successful status for the last TRB in a TD (the one with the
    IOC flag set).  On the second successful status, that warning will be
    triggered in the driver.
    
    Software is now supposed to not assume the TD is not completed until it
    gets that last successful status.  That means we have a slight race
    condition, although it should have little practical impact.  This patch
    papers over that issue.
    
    It's on my long-term to-do list to fix this race condition, but it is a
    much more involved patch that will probably be too big for stable.  This
    patch is needed for stable to avoid serious log spam.
    
    This patch should be backported to kernels as old as 3.0, that
    contain the commit ad808333 "Intel xhci:
    Ignore spurious successful event."
    
    The patch will have to be modified for kernels older than 3.2, since
    that kernel added the xhci_gen_setup function for xhci platform devices.
    The correct conflict resolution for kernels older than 3.2 is to set
    XHCI_SPURIOUS_SUCCESS in xhci_pci_quirks for all xHCI 1.0 hosts.
    Signed-off-by: NGeorge Cherian <george.cherian@ti.com>
    Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
    Cc: stable@vger.kernel.org
    07f3cb7c
xhci-pci.c 10.5 KB