Hi Henrik, 2011/8/13 Henrik Rydberg <rydberg@xxxxxxxxxxx>: >> > The device seems to send finger changes sequentually, resulting in one >> > packet (terminated with input sync) for each finger change. Is this >> > the intention/necessary? Some egalax firmware (hid version) seems to >> > work this way. >> >> When I make v2 patch, I've a look the Protocol B's driver in upstream, >> but there were two type of multi-point report fashion, >> One type is report all the finger status in one input sync(), and >> separate each mt point with mt_input_slot(), like wocom driver. >> >> But there was some driver (like egalax hid version), send each mt >> point with one input_sync(), but I'm worry about if main stream user >> space frameworks(xorg mtouch etc,) support this behavior well. > > Sequential reporting works reasonably well, although there are > potential problems (applying methods for smooth motion, for > instance). Wakeups and cpu intensity also increases. > >> What's your point of view about this ? > > If possible, I think batched reporting is preferred, i.e., using the > same method as all hid drivers _but_ the egalax one. After go through the code, I found HID driver's batched report is hard to implement in this driver. Although, since I already use threaded irq to deal with the new event information, and it will perform i2c read every time, i2c is a slow bus, I think the CPU cause of this kind of device is relative lower then some device via USB. > >> > The usage of REPORT_MODE_* is unclear to me too. >> >> In the programming manual this mode 's name is "single touch mouse >> mode", may be it will be a better name for this mode ? > > Ok, sounds like the equivalent of the hid generic mouse, which could > either be ignored or assigned its own input device node. Nothing out > of the ordinary, in other words, and the patch looks good in this > respect. Thanks for clarifying. > I've already change the MODE_SINGLE to MODE_MOUSE to avoid confusion in next version. > Henrik > Thanks, Jiejing -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
