• David Brownell's avatar
    [PATCH] Re: ohci-hcd and that NCR implementation ... · 5a346fe4
    David Brownell authored
    The attached patch makes the one SiS controller behave
    like the other... the key fix being wmb() to make sure that
    no writes are still in CPU caches before telling the HC it's
    OK to fetch the data.  (And a minor tweak to access PCI
    less often through the hub driver.)
    
    But the OPTi problem seems to be different.  Could you
    try this patch to see if it affects the problem your seeing
    with that NCR implementation?  And in any case, please
    integrate it to Linus' latest.  (Against 2.5.10, might be
    some fuzz on the pci tweak due to that warning fix.)
    
    Those missing wmb() statements have likely been the root
    cause of various usb-ohci flakes reported over time, too.
    The drivers are still almost identical in those areas.  (Though
    something made ohci-hcd consistently lose that cache flush
    race; maybe it's a bit faster.)
    5a346fe4
ohci-hub.c 6.66 KB