Hi, On Mittwoch, 4. Februar 2009, Ludovic Rousseau wrote: > 2009/2/3 Martin Preuss <aquaman...@gmx.de>: > > 1) with pcscd all readers are always *on*. As soon as a reader is > > connected it is started and polled for card insertion and removal even > > when there is no client. I would very much like the pcscd to only power > > up a reader if there is at least one client. This also serves as a nice > > visual control (on my system I have reason to be suspicious if a reader > > suddenly starts up unless I actually started a client myself). > > pcscd does not "power up [the] reader" but power up the _card_ even if > no application is using this reader/card. Is that what you wanted to > write? [...]
No, actually I meant the reader: Since the last few releases the Linux kernel has the USB suspend feature. Some readers (like newer cyberjacks) support this feature and and go into a low power consumption mode when USB suspend kicks in. However, since pcscd always opens the reader and asks every second or so about the card status this suspend mode never kicks in while pcscd is running. [...] > Or do you know a way to power on and off a reader? [...] Accessing the usb (e.g. opening the device file) leaves USB suspend mode, so even enumeration via libusb does that (enumerating the devices using libsysfs or libhal does not). About 2 secs after the last file descriptor is closed USB suspend is entered. [...] > You want non-blocking PC/SC functions? A non-blocking SCardTransmit for > example? This would be an evolution of PC/SC and should be defined by the > PC/SC workgroup and implemented by the other PC/SC "vendors" (Microsoft, > Apple, Sun). [...] In my posting I already admitted that this is quite unlikely to happen. However, at that point Alon's idea sound even more interesting. [...] > Good point. > But my target is not to ease the use of proprietary drivers. So it > will be a very low priority on my list. [...] It' not about proprietary drivers: It is about the security and stabilty of the daemon process. Even Open Source drivers might contain a bug or two... [...] > One important information would be to know the consumption of a reader > with a card powered up and the consumption of the same reader with the > card NOT powered up. I have no idea of the possible gain here. It may > be far much efficient to unplug the reader. [...] That has proven to be difficult for built-in readers ;-) Regards Martin -- "Things are only impossible until they're not" Martin Preuss - http://www2.aquamaniac.de/ AqBanking - http://www.aqbanking.de/ LibChipcard - http://www.libchipcard.de/ _______________________________________________ opensc-devel mailing list opensc-devel@lists.opensc-project.org http://www.opensc-project.org/mailman/listinfo/opensc-devel
