Re: [PATCH 1/4] input: Set default events per packet.
From: Jeffrey Brown <hidden>
Date: 2011-03-25 23:31:03
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lkml
On Fri, Mar 25, 2011 at 1:20 AM, Henrik Rydberg [off-list ref] wrote:
quoted
+static inline bool is_mt_axis(int axis) +{ + return axis == ABS_MT_SLOT || + (axis >= ABS_MT_FIRST && axis <= ABS_MT_LAST); +}It would be great to get this inline into input/mt.h instead.
Makes sense. I'll do that.
quoted
+ else if (test_bit(ABS_MT_TRACKING_ID, dev->absbit)) + mt_slots = dev->absinfo[ABS_MT_TRACKING_ID].maximum - + dev->absinfo[ABS_MT_TRACKING_ID].minimum + 1;This one is a bit iffy - the tracking id is not limited like this in mainline, looks like android usage. A test againts some arbitrary max should do it.
Yeah, I'm not sure about this one. Tracking ID could effectively have any range. All of the MT Protocol A touch screen drivers I have looked at, assuming they report tracking ids at all, report a reasonable upper bound on the contact points they support. Originally, I set an arbitrary maximum bound of 20 slots. In the interests of keeping it simple, I decided to remove that bound when I submitted the patch for review here. How about: mt_slots = min(MAX_MT_SLOTS_TO_INFER_FROM_TRACKING_ID_RANGE, dev->absinfo[ABS_MT_TRACKING_ID].maximum - dev->absinfo[ABS_MT_TRACKING_ID].minimum + 1); Where MAX_MT_SLOTS_TO_INFER_FROM_TRACKING_ID_RANGE is set to 32 or something. There's also the question of how many slots we should infer when neither ABS_MT_SLOT or ABS_MT_TRACKING_ID is available. The drivers I've seen that don't provide tracking ids, are very basic and tend to only support 2 touch points. I guess we could add a DEFAULT_NUMBER_OF_MT_SLOTS constant to handle that case. Please feel free to suggest better names for these constants. Jeff. -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html