[3.16.y-ckt stable] Patch "[media] tda1004x: only update the frontend properties if locked" has been added to the 3.16.y-ckt tree

[Luis Henriques]

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

    [media] tda1004x: only update the frontend properties if locked

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/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt25.

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

---8<------------------------------------------------------------

>From 6b33f7da25aaa5d361c11e0b6f83dd1e648db9ec Mon Sep 17 00:00:00 2001
From: Mauro Carvalho Chehab <mchehab at osg.samsung.com>
Date: Wed, 3 Feb 2016 17:33:48 -0200
Subject: [media] tda1004x: only update the frontend properties if locked

commit e8beb02343e7582980c6705816cd957cf4f74c7a upstream.

The tda1004x was updating the properties cache before locking.
If the device is not locked, the data at the registers are just
random values with no real meaning.

This caused the driver to fail with libdvbv5, as such library
calls GET_PROPERTY from time to time, in order to return the
DVB stats.

Tested with a saa7134 card 78:
	ASUSTeK P7131 Dual, vendor PCI ID: 1043:4862

Signed-off-by: Mauro Carvalho Chehab <mchehab at osg.samsung.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/media/dvb-frontends/tda1004x.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/media/dvb-frontends/tda1004x.c b/drivers/media/dvb-frontends/tda1004x.c
index a2631be7ffac..08e0f0dd8728 100644
--- a/drivers/media/dvb-frontends/tda1004x.c
+++ b/drivers/media/dvb-frontends/tda1004x.c
@@ -903,9 +903,18 @@ static int tda1004x_get_fe(struct dvb_frontend *fe)
 {
 	struct dtv_frontend_properties *fe_params = &fe->dtv_property_cache;
 	struct tda1004x_state* state = fe->demodulator_priv;
+	int status;

 	dprintk("%s\n", __func__);

+	status = tda1004x_read_byte(state, TDA1004X_STATUS_CD);
+	if (status == -1)
+		return -EIO;
+
+	/* Only update the properties cache if device is locked */
+	if (!(status & 8))
+		return 0;
+
 	// inversion status
 	fe_params->inversion = INVERSION_OFF;
 	if (tda1004x_read_byte(state, TDA1004X_CONFC1) & 0x20)