[3.16.y-ckt stable] Patch "[media] img-ir/hw: Always read data to clear buffer" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    [media] img-ir/hw: Always read data to clear buffer

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt4.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 1817fca3f97d712c909a367298bad4f0984f13c6 Mon Sep 17 00:00:00 2001
From: Dylan Rajaratnam <dylan.rajaratnam at imgtec.com>
Date: Mon, 17 Nov 2014 09:17:45 -0300
Subject: [media] img-ir/hw: Always read data to clear buffer

commit ea0de4ec5489da0fe738b274effac4f950e93d76 upstream.

A problem was found on Polaris where if the unit it booted via the power
button on the infrared remote then the next button press on the remote
would return the key code used to power on the unit.

The sequence is:
 - The polaris powered off but with the powerdown controller (PDC) block
   still powered.
 - Press power key on remote, IR block receives the key.
 - Kernel starts, IR code is in IMG_IR_DATA_x but neither IMG_IR_RXDVAL
   or IMG_IR_RXDVALD2 are set.
 - Wait any amount of time.
 - Press any key.
 - IMG_IR_RXDVAL or IMG_IR_RXDVALD2 is set but IMG_IR_DATA_x is
   unchanged since the powerup key data was never read.

This is worked around by always reading the IMG_IR_DATA_x in
img_ir_set_decoder(), rather than only when the IMG_IR_RXDVAL or
IMG_IR_RXDVALD2 bit is set.

Signed-off-by: Dylan Rajaratnam <dylan.rajaratnam at imgtec.com>
Signed-off-by: James Hogan <james.hogan at imgtec.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab at osg.samsung.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/media/rc/img-ir/img-ir-hw.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/media/rc/img-ir/img-ir-hw.c b/drivers/media/rc/img-ir/img-ir-hw.c
index 0127dd257a57..5dfd0e9c2d5a 100644
--- a/drivers/media/rc/img-ir/img-ir-hw.c
+++ b/drivers/media/rc/img-ir/img-ir-hw.c
@@ -542,10 +542,12 @@ static void img_ir_set_decoder(struct img_ir_priv *priv,
 	if (ir_status & (IMG_IR_RXDVAL | IMG_IR_RXDVALD2)) {
 		ir_status &= ~(IMG_IR_RXDVAL | IMG_IR_RXDVALD2);
 		img_ir_write(priv, IMG_IR_STATUS, ir_status);
-		img_ir_read(priv, IMG_IR_DATA_LW);
-		img_ir_read(priv, IMG_IR_DATA_UP);
 	}

+	/* always read data to clear buffer if IR wakes the device */
+	img_ir_read(priv, IMG_IR_DATA_LW);
+	img_ir_read(priv, IMG_IR_DATA_UP);
+
 	/* stop the end timer and switch back to normal mode */
 	del_timer_sync(&hw->end_timer);
 	hw->mode = IMG_IR_M_NORMAL;
--
2.1.4