Re: autosuspend for hid
Oliver Neukum <[email protected]>
| Newsgroups | gmane.linux.usb.devel |
|---|---|
| Organization | Novell |
| Message-ID | <[email protected]> |
Am Mittwoch, 16. Mai 2007 08:41 schrieb Robert Marquardt: > Oliver Neukum schrieb: > > Am Dienstag, 15. Mai 2007 16:43 schrieb Robert Marquardt: > >> Oliver Neukum schrieb: > >> > >>> The main problem implementing this is LEDs. HID has the very though > >>> property of initiating output to them without user space's involvement > >>> from interrupt context to all attached devices. Doing this with suspended > >>> devices is problematic. > >> Is that setting the keyboard LEDs? > > > > That I've tested it with. But the HID spec is very versatile. Other devices > > can use it, too. > > > > Regards > > Oliver > > > > Writing reports to a device from kernel? Why would that be needed? It is in my experience mainly needed for setting and clearing the LEDs. But I don't claim to know all input devices in the kernel tree. > I even see no reason to do it at all. The virtual keyboard should live > at the border to user mode or even fully in user mode. There should only > two system devices (like in Windows) mouse and keyboard. Only keyboards The mouse is not a system device in that sense. > are writable at all (mice may be writable, but not from the virtual > mouse point of view). Preserving the LEDs working under the worst circumstances is important. I am not sure whether it is a good thing that all keyboards share CAPS LOCK, etc... , but that's a wider issue. Regards Oliver ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel