Messages in this thread | | | Date | Mon, 22 Nov 2010 13:09:57 -0500 (EST) | From | Alan Stern <> | Subject | Re: [Stable-review] [39/45] OHCI: work around for nVidia shutdown problem |
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On Mon, 22 Nov 2010, Greg KH wrote:
> On Sat, Nov 20, 2010 at 11:51:39AM -0500, Alan Stern wrote: > > On Sat, 20 Nov 2010, Ben Hutchings wrote: > > > > > On Fri, 2010-11-19 at 13:43 -0800, Greg KH wrote: > > > > 2.6.32-stable review patch. If anyone has any objections, please let us know. > > > > > > > > ------------------ > > > > > > > > From: Alan Stern <stern@rowland.harvard.edu> > > > > > > > > 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. > > > [...] > > > > > > This last bit seems like a major change in behaviour, and this commit > > > has only just gone into the 2.6.37 cycle. How thoroughly has this been > > > tested on other OHCI controllers? Wouldn't it make more sense to use > > > the same quirk condition? > > > > Ben is right; let's hold off on putting this patch into any of the > > stable kernels. There has been a bug report submitted against it, > > Bugzilla #22562. > > Good point, I'll go drop it. > > Alan, when it all gets worked out, care to resend it to > stable@kernel.org?
Sure.
Alan Stern
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