[media] ir-kbd-i2c: improve remote behavior with z8 behind usb

Add the same "are you ready?" i2c_master_send() poll command to
get_key_haup_xvr found in lirc_zilog, which is apparently seen in
the Windows driver for the PVR-150 w/a z8. This stabilizes what is
received from both the HD-PVR and HVR-1950, even with their polling
intervals at the default of 100, thus the removal of the custom
260ms polling_interval in pvrusb2-i2c-core.c.

Acked-by: Andy Walls <awalls@md.metrocast.net>
Acked-by: Mike Isely <isely@isely.net>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/media/video/ir-kbd-i2c.c b/drivers/media/video/ir-kbd-i2c.c
index d2b20ad..a221ad6 100644
--- a/drivers/media/video/ir-kbd-i2c.c
+++ b/drivers/media/video/ir-kbd-i2c.c
@@ -128,6 +128,19 @@ static int get_key_haup(struct IR_i2c *ir, u32 *ir_key, u32 *ir_raw)
 
 static int get_key_haup_xvr(struct IR_i2c *ir, u32 *ir_key, u32 *ir_raw)
 {
+	int ret;
+	unsigned char buf[1] = { 0 };
+
+	/*
+	 * This is the same apparent "are you ready?" poll command observed
+	 * watching Windows driver traffic and implemented in lirc_zilog. With
+	 * this added, we get far saner remote behavior with z8 chips on usb
+	 * connected devices, even with the default polling interval of 100ms.
+	 */
+	ret = i2c_master_send(ir->c, buf, 1);
+	if (ret != 1)
+		return (ret < 0) ? ret : -EINVAL;
+
 	return get_key_haup_common (ir, ir_key, ir_raw, 6, 3);
 }