On 06/03/2015 02:31 PM, Matt Whitlock wrote: > On Wednesday, 3 June 2015, at 2:24 pm, Henrik Rydberg wrote: >>> This patch changes the report_synaptics_data() function so that it reports >>> the highest touch_major and highest tool_major of any touching finger as >>> ABS_PRESSURE and ABS_TOOL_WIDTH, respectively. >> >> I appreciate the problem, but I would much rather have bcm5974 converted >> to use input_mt_report_pointer_emulation() instead. The emulation code >> has been left as is for a long while, but this seems to be a good time >> to convert it. > > report_tp_state() calls input_mt_sync_frame(), which in turn calls > input_mt_report_pointer_emulation() already. So does this mean that > report_synaptics_data() can be removed entirely? >
The bcm5974 driver does not advertise ABS_MT_PRESSURE, and therefore ABS_PRESSURE is not reported via input_mt_sync_frame(). Furthermore, ABS_TOOL_WIDTH is not handled at all in input_mt_report_pointer_emulation(). To handle pressure automatically, one would need to advertise (and use) ABS_MT_PRESSURE. There is a misnomer in the driver, let say for historical reasons, so that ABS_MT_TOUCH_MAJOR gets reported in the ABS_PRESSURE field. This is a bit of a problem, but quite solvable. For tool width, it is hard to imagine ever being able to remove that functionality completely. However, it can be transferred to input_mt_report_pointer_emulation() instead, provided every user of that function is analyzed for consequences and usage of ABS_MT_WIDTH_MAJOR. It would be great to simply remove report_synaptics_data(), if possible, retaining the precise behavior. Barring the bug, of course. Thanks, Henrik -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
