On Mon, 25 Apr 2011, Willy Tarreau wrote: > 2.6.27.59-stable review patch. If anyone has any objections, please let us > know. > > ------------------ > > From: Alan Stern <[email protected]> > > commit 3df7169e73fc1d71a39cffeacc969f6840cdf52b upstream. > > This patch (as1417) fixes a problem affecting some (or all) nVidia > chipsets. When the computer is shut down, the OHCI controllers > continue to power the USB buses and evidently they drive a Reset > signal out all their ports. This prevents attached devices from going > to low power. Mouse LEDs stay on, for example, which is disconcerting > for users and a drain on laptop batteries. > > The fix involves leaving each OHCI controller in the OPERATIONAL state > during system shutdown rather than putting it in the RESET state. > Although this nominally means the controller is running, in fact it's > not doing very much since all the schedules are all disabled. However > there is ongoing DMA to the Host Controller Communications Area, so > the patch also disables the bus-master capability of all PCI USB > controllers after the shutdown routine runs. > > The fix is applied only to nVidia-based PCI OHCI controllers, so it > shouldn't cause problems on systems using other hardware. As an added > safety measure, in case the kernel encounters one of these running > controllers during boot, the patch changes quirk_usb_handoff_ohci() > (which runs early on during PCI discovery) to reset the controller > before anything bad can happen. > > Reported-by: Pali Rohár <[email protected]> > Signed-off-by: Alan Stern <[email protected]> > CC: David Brownell <[email protected]> > Tested-by: Pali Rohár <[email protected]> > Signed-off-by: Greg Kroah-Hartman <[email protected]>
Some people have reported that more recent Nvidia systems work correctly without this patch and have problems when the patch is applied. For now, I suggest omitting this patch. Alan Stern _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
