-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 04/08/10 16:25, Henrik Rydberg wrote: > Rafi Rubin wrote: >> On 04/08/2010 05:43 AM, Henrik Rydberg wrote: >>> Michael Poole wrote: >>> [...] >>>> >>>> How would the slot number for a contact be chosen? >>> >>> The device driver determines how to use the slots. The driver calls >>> input_mt_slot(dev, slot), sends the data for the slot, picks another >>> slot, and >>> repeats. >>> >> >> Is there any particular downside to defaulting to implicit slot ids? > > Yes. The device driver should not have to update every slot between > synchronizations, or the point would be lost. > >> For drivers/hardware that don't handle tracking, SYN_MT_REPORT could >> just result in dev->slot++ and a SYN_REPORT resets dev->slot to 0; > > Drivers that do not handle tracking should not use the slots at all. The slot > concept requires that whatever gets communicated over it is identifiable, or > else it would not be possible to send changes. Drivers without tracking > capabilities should stick to the current MT protocol, for which it was designed. That's unfortunate. I think tracking upsets are generally quite rare (at least for the n-trig hardware), and we would see most of the benefit of jitter and bandwidth reduction even if we use contact ordering for slots. Tracking upsets would still flow downstream, a large state change should cause the slot to emit the new position. I was also hoping the slotting mechanism might be a good place to inject generic tracking support later. Rafi -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAku+SWcACgkQwuRiAT9o60894wCg1lQIzcFgmUNqUpiKJSDigxNE QVcAn3YylXnlNaieGTJyQ2UblpqR5X7q =EokA -----END PGP SIGNATURE----- -- 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
