[PATCH 4.4 44/74] [media] adv7604: fix tx 5v detect regression

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Hans Verkuil <hansverk@xxxxxxxxx>

commit 0ba4581c84cfb39fd527f6b3457f1c97f6356c04 upstream.

The 5 volt detect functionality broke in 3.14: the code reads IO register 0x70
again after it has already been cleared. Instead it should use the cached
irq_reg_0x70 value and the io_write to 0x71 to clear 0x70 can be dropped since
this has already been done.

Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/media/i2c/adv7604.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/media/i2c/adv7604.c
+++ b/drivers/media/i2c/adv7604.c
@@ -1960,10 +1960,9 @@ static int adv76xx_isr(struct v4l2_subde
 	}
 
 	/* tx 5v detect */
-	tx_5v = io_read(sd, 0x70) & info->cable_det_mask;
+	tx_5v = irq_reg_0x70 & info->cable_det_mask;
 	if (tx_5v) {
 		v4l2_dbg(1, debug, sd, "%s: tx_5v: 0x%x\n", __func__, tx_5v);
-		io_write(sd, 0x71, tx_5v);
 		adv76xx_s_detect_tx_5v_ctrl(sd);
 		if (handled)
 			*handled = true;