On Tue, 26 Jul 2011, Seth Forshee wrote: > On Sat, Jul 23, 2011 at 09:56:15PM -0400, Alan Stern wrote: > > On Sat, 23 Jul 2011, Seth Forshee wrote: > > > > > After experimenting with this device more I came to the conclusion that > > > the normal behavior with this machine is for the card reader to be > > > disconnected from the USB bus unless there's a card in the slot. During > > > a normal boot with an empty card slot the card reader never shows up on > > > the bus. > > > > Weird. Then the reader would never be usable. Unless it connects > > itself to the bus when a card is inserted? > > Yes, the reader is connected to the bus when a card is inserted. Remove > the card and it disappears again. That's the first time I've heard of such a thing. > > > The only solution I've come up with is to leave usb-stor-scan freezable > > > without allowing it to actually freeze. We can request a fake signal be > > > sent when freezing and use interruptible sleep to abort the wait early > > > and finish up the thread's processing. This is implemented in the patch > > > below. Does this approach look reasonable? It's rather subtle, but it > > > does seem to work. I done numerous S4 cycles with and without a card > > > inserted and didn't get any failures. > > > > This runs the risk of failing to suspend if scanning takes too long. > > It may increase the exposure to that risk, but really the risk is > already there. True. Once the scanning begins there's no way to freeze the thread, even in the current code. > > On the other hand, many systems nowadays use async scanning anyway. > > And that combination of events isn't too likely to happen, whereas > > you're facing a real problem right now. So I guess this is okay. > > Great, thanks. > > Will the patch get picked up from my previous email, or do I need to > resend it? You should resend it to Greg, and you can add Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> 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
