HID: usbhid: enable always-poll quirk for Elan Touchscreen

Enable the always-poll quirk for Elan Touchscreens found on some recent
Samsung laptops.

Without this quirk the device keeps disconnecting from the bus (and is
re-enumerated) unless opened (and kept open, should an input event
occur).

Note that while the device can be run-time suspended, the autosuspend
timeout must be high enough to allow the device to be polled at least
once before being suspended. Specifically, using autosuspend_delay_ms=0
will still cause the device to disconnect on input events.

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-ids.h

@@ -296,6 +296,9 @@
 #define USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_73F7	0x73f7
 #define USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_A001	0xa001
 
+#define USB_VENDOR_ID_ELAN		0x04f3
+#define USB_DEVICE_ID_ELAN_TOUCHSCREEN	0x0089
+
 #define USB_VENDOR_ID_ELECOM		0x056e
 #define USB_DEVICE_ID_ELECOM_BM084	0x0061
 

drivers/hid/usbhid/hid-quirks.c

@@ -70,6 +70,7 @@ static const struct hid_blacklist {
 	{ USB_VENDOR_ID_CH, USB_DEVICE_ID_CH_3AXIS_5BUTTON_STICK, HID_QUIRK_NOGET },
 	{ USB_VENDOR_ID_CH, USB_DEVICE_ID_CH_AXIS_295, HID_QUIRK_NOGET },
 	{ USB_VENDOR_ID_DMI, USB_DEVICE_ID_DMI_ENC, HID_QUIRK_NOGET },
+	{ USB_VENDOR_ID_ELAN, USB_DEVICE_ID_ELAN_TOUCHSCREEN, HID_QUIRK_ALWAYS_POLL },
 	{ USB_VENDOR_ID_ELO, USB_DEVICE_ID_ELO_TS2700, HID_QUIRK_NOGET },
 	{ USB_VENDOR_ID_FORMOSA, USB_DEVICE_ID_FORMOSA_IR_RECEIVER, HID_QUIRK_NO_INIT_REPORTS },
 	{ USB_VENDOR_ID_FREESCALE, USB_DEVICE_ID_FREESCALE_MX28, HID_QUIRK_NOGET },