> > Propagating information about various sensor defects to userspace > > sounds horrid to me. The sooner we can forget about these devices, the > > better. > > Not providing the userspace driver with enough information to give > users the best experience possible sounds horrid to me. The question was whether we should add those to the long-lived input interface or not, sorry if that sounded like a rant. > It turns out > that using a bounding box with fixed "[(min_x, min_y), (max_x, > max_y)]", and no per-finger pressure information, instead of the > coordinates and pressures provided by the firmware, is throwing away > useful data that could be used by the userspace driver. So far, we have provided the baseline of reliable data from similar devices. > What we would like is a way to tell userspace what the firmware > originally intended, but with a caveat that the firmware can't be 100% > trusted. And, since this is for a relatively small class of hardware, > to do it in a way that doesn't consume precious resources, like > additional input properties. Input properties are not a precious resource, there is no limit on the bitmask values or anything like that, but there is no rush to add new ones. > >> > > * Leave the device as SEMI_MT, but provide the real locations, and > >> > > allow userspace to determine the device vendor/model/etc. If > >> > > userspace knows that a specific device behaves in a specific way, it > >> > > can do its own quirking handling. Given the specificity of this > >> > > behavior to only some devices of one brand, this would be my > >> > > suggested resolution to the issue. > >> > > > This is essentially what this patch does. I am interpreting Chase's suggestion as simply reporting the raw values instead of min/max. > It sets the SEMI_MT flag to > indicate that the kernel data cannot be totally trusted, and then > provides real MT-B (including per-finger pressures), instead of a > fixed bounding box. It leaves it to userspace to treat the two slots > worth of coordinates as a bounding box or as actual fingers using its > own heuristics. By limiting to only one hardware type (using DMI), > any breakage caused by this alternative use of the SEMI_MT flag is > limited. So it seems there is no need to add logic to the driver, only change one line from min/max to raw data for this particular hardware. That would solve your problem, yes? > Hopefully it is clear what we are trying to accomplish. I don't see > how we can make a bounding box, even an improved bounding box, work. > Perhaps Henrik has a really good idea, but I haven't been able to > figure out what he is suggesting. I understand you are not interested in looking into this, and your main objective is quite clear. Thanks, Henrik -- 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
