On Tue, 10 Jul 2012 00:54:54 +0200 Christian Lamparter <chunk...@googlemail.com> wrote:
> On Monday, July 09, 2012 11:59:39 PM Andrew Morton wrote: > > On Fri, 6 Jul 2012 14:30:16 -0700 > > Greg KH <gre...@linuxfoundation.org> wrote: > > > > > On Fri, Jul 06, 2012 at 11:23:52PM +0200, Christian Lamparter wrote: > > > > The idea of moving rebind procedure into pm.complete > > > > was taken from the usb-subsystem, which has similar > > > > problems with reattaching devices during/after > > > > resume. > > > > > > > > Signed-off-by: Christian Lamparter <chunk...@googlemail.com> > > > > --- > > > > To Greg: > > > > > > > > I have submitted this patch back in March and again in May. > > > > As far as I can tell it was neither rejected nor was it > > > > accepted into linux-pcmcia.git since. So I'm asking you, > > > > if you could take the patch instead... please. > > > > > > There is a PCMCIA "team" who should be taking these types of patches. > > > Why are they not doing so? > > > > > > > Things are pretty quiet in pcmcia world, but Dominik does appear to > > still be doing stuff. > > > > I sometimes queue PCMCIA patches for people, but not this one. The > > changelog is just junk. What does the patch do? Why does it do it? > > What problems does it solve? What are these mysterious "problems with > > reattaching devices" to which it refers? Useless... > > > Well, that can be improved, but it is a bit tricky. > AFAICT the usb subsystem dealt with pm in this commit: > > "commit 5096aedcd2eb70fbea83f09281f97f9ec973d9de > Author: Alan Stern <st...@rowland.harvard.edu> > Date: Tue Aug 12 14:34:14 2008 -0400 > > USB: Don't rebind before "complete" callback > > [...] We are not allowed to call drivers' probe routines during > a system sleep transition between the "prepare" and "complete" > callbacks, but that's exactly what we do when a driver doesn't > have full suspend/resume support. [...]" > > And on the pcmcia subsystem we have this: > > "commit 88b060d6c03fcb9e4d2018b4349954c4242a5c7f > Author: Dominik Brodowski <li...@dominikbrodowski.net> > Date: Sat Jan 2 14:14:23 2010 +0100 > > pcmcia: improve check for same card in slot after resume > > During a suspend/resume cycle, an user may change the card in the > PCMCIA/CardBus slot. [...] > > For CardBus devices, the PCI hotplug interface doesn't offer a "rescan" > facility which also _removes_ devices no longer to be found behind a > bridge. Therefore, remove and re-add all devices unconditionally." > > Unfortunately, the "re-add" is currently done in the *pm resume* callback > (socket_late_resume), but according to "USB: Don't rebind..." is not > allowed to have it there, so the patch moves it into the *pm complete* > callback. The Documentation/power/* contains mostly informations for > drivers developers, but AFAICT it doesn't say much about the subsystem > to which the device is connected should behave, so there's a bit of a > "citing-gap". hm, it does seem a bit of a screwup. What's unclear to me is whether your patch fixes any observed runtime problems. Or adds any runtime problems, which looks to be a distinct possibility. > So, my question now: Would you accept the pcmcia patch if I add the > "USB: Don't rebind..." as a reference to why the re-add needs to be > done in complete? Or do you think that I should bug the pm people > (and Alan - since he wrote that it is "not allowed") in this case > so I can link their official answer to this patch? Well I could grab it and give it a little bit of testing in linux-next. But I'd be super-reluctant to send such a patch upstream without detailed input from Alan/Greg/Rafael/Dominik/etc. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
