David Herrmann <dh.herrmann@xxxxxxxxx> wrote: >Hi > >On Sat, Sep 7, 2013 at 11:20 AM, Benjamin Tissoires ><benjamin.tissoires@xxxxxxxxx> wrote: >> >> >> On 07/09/13 10:57, David Herrmann wrote: >>> Hi >>> >>> On Sat, Sep 7, 2013 at 10:24 AM, Benjamin Tissoires >>>> I'm not particularly in favor of adding semantic between ABS_MISC >and >>>> ABS_MT_SLOT. We already did that once with the ABS_MT_* stuff, and >the >>>> problem comes from devices showing several axes, not really mapped >>>> (like joysticks). These axes are all mapped to ABS_MISC, but the >input >>>> core function map them to ABS_MISC+N. This way some joysticks show >>>> multitouch axes and are treated as such, whereas the axis are just >>>> regular absolute axes. (not sure I am clear enough... :( ) >>>> >>>> Currently, nothing is done in X or in Wayland to detect these false >>>> multitouch devices with a large number of absolute axes. But if we >>>> keep a hole between ABS_MISC and ABS_MT_SLOT, we could add an >>>> heuristic like: >>>> "if all the axes between ABS_MISC and ABS_MT_SLOT are available, >then >>>> ABS_MT_SLOT does not mean multitouch, but ABS_MISC+6." >>> >>> So Xorg just took control over the unused ABS_* slots? Hmm, then I >>> have no other idea than reverting the 3 patches. >>> Sadly, that also means there's no way for us to easily extend the >>> ABS_* bits. If someone has an idea, let me know. But for now I'll >just >>> put the drums/guitar patches on hold. >>> >> >> Well, I would say the "problem" lies in hid-input.c, line 919: >>>>>>>>>>>>>>>>>>>> >> while (usage->code <= max && test_and_set_bit(usage->code, >bit)) >> usage->code = find_next_zero_bit(bit, max + 1, >usage->code); >>>>>>>>>>>>>>>>>>>> >> >> So if you try to map several times ABS_MISC or any other axis, then >you are mapping ABS_MISC+N. >> >> Anyway, the only problematic axis is ABS_MISC, as it is a default >fallback. IMO, we can extend the ABS_* definitions after ABS_MT_TOOL_Y, >like the original patch you proposed without having to deal with the >above problem (though this will report the patch series to v3.13). >> To prevent future mistakes, we should just define ABS_MISC0 (0x29) to >ABS_MISC5 (0x2e) to fill the hole. > >As mentioned earlier in this thread, ABS_* is limited to 0x3f, so we >have only 2 more free slots after ABS_MT_TOOL_Y. >We will figure something out for 3.13. > >I will also prepare a patch for ABS_MISC0-MISC5. > Regardless of whether we settle on using lower bits or bite the bullet and extend number of axis I think it's time for EVIOCGABS2 that would take axis in its argument instead of encoding it in ioctl number - that idea wasn't that good. Thanks. -- Dmitry -- 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
