Re: [PATCH v3 02/49] Input: introduce input_mt_report_slot_inactive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi Henrik


On 2019/09/18 3:25, Henrik Rydberg wrote:
Hi Jiada,

input_mt_report_slot_state() ignores the tool when the slot is closed.
which has caused a bit of confusion.
This patch introduces input_mt_report_slot_inactive() to report slot
inactive state.
replaces all input_mt_report_slot_state() with
input_mt_report_slot_inactive() in case of close of slot.

This patch looks very odd, I am afraid.

When a driver needs to use input_mt functions, it first calls input_mt_init_slots() during setup. The MT state then remains in effect until the driver is destroyed. Thus, there is no valid case when input_mt_report_slot_state() would fail to execute the line

    input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1)

when active == false.

What input_mt_report_slot_state() does do, however, is to ignore the event when no MT state has been set, which does happen for some drivers handling both normal and MT devices. Changing such a driver in the way you suggest would introduce new events in existing, working cases, and possibly break userspace. We should try very hard to avoid it.


thanks for your comment,

Just to make sure, I think your comment is for
patch "[PATCH v3 01/49] Input: switch to use return value of input_mt_report_slot_state" not for "[PATCH v3 02/49] Input: introduce input_mt_report_slot_inactive", right?

yes, I agree
by having change:

-    input_mt_report_slot_state(dev, tool_type, active);
-    if (active) {
+        if (input_mt_report_slot_state(dev, tool_type, active)){
             ... ...
     }

the logic of the driver is changed, when (mt == NULL && active == true).
I will drop patch "Input: switch to use return value of" in next version

Thanks,
Jiada

Thanks,

Henrik





[Index of Archives]     [Linux Media Devel]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Linux Wireless Networking]     [Linux Omap]

  Powered by Linux