On Tue, 17 Apr 2012, Greg KH wrote: > On Tue, Apr 17, 2012 at 03:23:25PM -0400, Alan Stern wrote: > > This patch (as1541) corrects a small mistake in ehci-hcd. The IAAD > > (Interrupt on Async Advance Doorbell) bit in the USBCMD register is > > designed, as its name says, to act as a "doorbell". That is, the > > driver activates the bit by setting it to 1, and the hardware > > deactivates it later by setting it back to 0. The driver cannot clear > > the bit by writing a 0 to it; such writes are simply ignored. > > > > Therefore there is no reason for ehci-hcd to try to clear the bit. > > The patch removes the two instances where such attempts occur. > > > > Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> > > Is this for 3.4 or 3.5? 3.5. This isn't really a bug, because it won't cause any problems. The patch simply removes a couple of unnecessary do-nothing writes to a device register. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
