Thread (7 messages) flat view 7 messages, 2 authors, 2016-03-01

Re: [PATCH 3/3] goldfish: multitouch: no extra EV_SYN

From: Alan Cox <hidden>
Date: 2016-03-01 23:27:29

quoted
 	input_event(edev->input, type, code, value);
-	input_sync(edev->input);
+	/*
+	 * 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.
That would be error in that keyboard driver and should be fixed.
Agreed but it's still the case that current and long standing Goldfish
behaviour requires the above.
quoted
+	 * 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);

I'd rather we always rely on the host to send the SYN event.
That would certainly make sense for the future.
quoted
+
 	return IRQ_HANDLED;
 }
 
@@ -154,6 +173,15 @@ 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.
+	 * 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.
+	 * See drivers/input/input.c:input_handle_abs_event.
+	 */
+	input_mt_init_slots(input_dev, GOLDFISH_MAX_FINGERS, 0);
Can we use data retrieved by events_import_abs_params() to set up
correct number of slots? Also we need error handling. And possibly
retrieve correct properties to set pass to input_mt_init_slots()...
Again - I agree that makes sense for future versions of Goldfish

Alan
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help