Patch "[media] v4l: tvp5150: Reset device at probe time, not in get/set format handlers" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    [media] v4l: tvp5150: Reset device at probe time, not in get/set format handlers

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     v4l-tvp5150-reset-device-at-probe-time-not-in-get-set-format-handlers.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From aff808e813fc2d311137754165cf53d4ee6ddcc2 Mon Sep 17 00:00:00 2001
From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: Fri, 9 Dec 2016 09:47:17 -0200
Subject: [media] v4l: tvp5150: Reset device at probe time, not in get/set format handlers

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

commit aff808e813fc2d311137754165cf53d4ee6ddcc2 upstream.

The tvp5150 doesn't support format setting through the subdev pad API
and thus implements the set format handler as a get format operation.
The single handler, tvp5150_fill_fmt(), resets the device by calling
tvp5150_reset(). This causes malfunction as the device can be reset at
will, possibly from userspace when the subdev userspace API is enabled.

The reset call was added in commit ec2c4f3f93cb ("[media] media:
tvp5150: Add mbus_fmt callbacks"), probably as an attempt to set the
device to a known state before detecting the current TV standard.
However, the get format handler doesn't access the hardware to get the
TV standard since commit 963ddc63e20d ("[media] media: tvp5150: Add
cropping support"). There is thus no need to reset the device when
getting the format.

However, removing the tvp5150_reset() from the get/set format handlers
results in the function not being called at all if the bridge driver
doesn't use the .reset() operation. The operation is nowadays abused and
shouldn't be used, so shouldn't expect bridge drivers to call it. To
make sure the device is properly initialize, move the reset call from
the format handlers to the probe function.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/media/i2c/tvp5150.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

--- a/drivers/media/i2c/tvp5150.c
+++ b/drivers/media/i2c/tvp5150.c
@@ -858,8 +858,6 @@ static int tvp5150_fill_fmt(struct v4l2_
 
 	f = &format->format;
 
-	tvp5150_reset(sd, 0);
-
 	f->width = decoder->rect.width;
 	f->height = decoder->rect.height / 2;
 
@@ -1521,7 +1519,6 @@ static int tvp5150_probe(struct i2c_clie
 		res = core->hdl.error;
 		goto err;
 	}
-	v4l2_ctrl_handler_setup(&core->hdl);
 
 	/* Default is no cropping */
 	core->rect.top = 0;
@@ -1532,6 +1529,8 @@ static int tvp5150_probe(struct i2c_clie
 	core->rect.left = 0;
 	core->rect.width = TVP5150_H_MAX;
 
+	tvp5150_reset(sd, 0);	/* Calls v4l2_ctrl_handler_setup() */
+
 	res = v4l2_async_register_subdev(sd);
 	if (res < 0)
 		goto err;


Patches currently in stable-queue which might be from laurent.pinchart@ideasonboard.com are

queue-4.9/v4l-tvp5150-reset-device-at-probe-time-not-in-get-set-format-handlers.patch
queue-4.9/v4l-tvp5150-fix-comment-regarding-output-pin-muxing.patch
queue-4.9/v4l-tvp5150-don-t-override-output-pinmuxing-at-stream-on-off-time.patch