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Commit 94a421ba authored by Lingfeng Yang's avatar Lingfeng Yang Committed by Amit Pundir
Browse files

ANDROID: input: goldfish_events: no extra EV_SYN; register goldfish 



If we send SYN_REPORT on every single
multitouch event, it breaks the multitouch.

The multitouch becomes janky and
having to click 2-3 times to
do stuff (plus randomly activating notification
bars when not clicking)

If we suppress these SYN_REPORTS,
multitouch will work fine, plus the events
will have a protocol that looks nice.

In addition, we need to register Goldfish Events
as a multitouch device by issuing
input_mt_init_slots, otherwise
input_handle_abs_event in drivers/input/input.c
will silently drop all ABS_MT_SLOT events,
making it so that touches with more than 1 finger
do not work properly.

Signed-off-by: default avatar"Lingfeng Yang" <lfy@google.com>
Change-Id: Ib2350f7d1732449d246f6f0d9b7b08f02cc7c2dd
(cherry picked from commit 6cf40d0a16330e1ef42bdf07d9aba6c16ee11fbc)
parent 29be5c0c

drivers/input/keyboard/goldfish_events.c

+27 −1
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include <linux/interrupt.h>

#include <linux/types.h>

#include <linux/input.h>

#include <linux/input/mt.h>

#include <linux/kernel.h>

#include <linux/platform_device.h>

#include <linux/slab.h>
@@ -24,6 +25,8 @@ 
#include <linux/io.h>

#include <linux/acpi.h>



#define GOLDFISH_MAX_FINGERS 5



enum {

	REG_READ        = 0x00,

	REG_SET_PAGE    = 0x00,
@@ -52,7 +55,21 @@ static irqreturn_t events_interrupt(int irq, void *dev_id) 
	value = __raw_readl(edev->addr + REG_READ);



	input_event(edev->input, type, code, value);

	// Send an extra (EV_SYN, SYN_REPORT, 0x0) event

	// if a key was pressed. Some keyboard device

        // drivers may only send the EV_KEY event and

        // not EV_SYN.

        // Note that sending an extra SYN_REPORT is not

        // necessary nor correct protocol with other

        // devices such as touchscreens, which will send

        // their own SYN_REPORT's when sufficient event

        // information has been collected (e.g., for

        // touchscreens, when pressure and X/Y coordinates

	// have been received). Hence, we will only send

	// this extra SYN_REPORT if type == EV_KEY.

	if (type == EV_KEY) {

		input_sync(edev->input);

	}

	return IRQ_HANDLED;

}
@@ -154,6 +171,15 @@ static int events_probe(struct platform_device *pdev) 


	input_dev->name = edev->name;

	input_dev->id.bustype = BUS_HOST;

	// Set the Goldfish Device to be multi-touch.

	// In the Ranchu kernel, there is multi-touch-specific

	// code for handling ABS_MT_SLOT events.

	// See drivers/input/input.c:input_handle_abs_event.

	// If we do not issue input_mt_init_slots,

        // the kernel will filter out needed ABS_MT_SLOT

        // events when we touch the screen in more than one place,

        // preventing multi-touch with more than one finger from working.

	input_mt_init_slots(input_dev, GOLDFISH_MAX_FINGERS, 0);



	events_import_bits(edev, input_dev->evbit, EV_SYN, EV_MAX);

	events_import_bits(edev, input_dev->keybit, EV_KEY, KEY_MAX);