[4.2.y-ckt stable] Patch "[media] bttv: Width must be a multiple of 16 when capturing planar formats" has been added to the 4.2.y-ckt tree

[Kamal Mostafa]

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

    [media] bttv: Width must be a multiple of 16 when capturing planar formats

to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-4.2.y-queue

This patch is scheduled to be released in version 4.2.8-ckt7.

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

For more information about the 4.2.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

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

>From 41c3908265700037e400c06ea95f7445d29cc982 Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede at redhat.com>
Date: Sun, 7 Feb 2016 09:24:29 -0200
Subject: [media] bttv: Width must be a multiple of 16 when capturing planar
 formats

commit 5c915c68763889f0183a1cc61c84bb228b60124a upstream.

On my bttv card "Hauppauge WinTV [card=10]" capturing in YV12 fmt at max
size results in a solid green rectangle being captured (all colors 0 in
YUV).

This turns out to be caused by max-width (924) not being a multiple of 16.

We've likely never hit this problem before since normally xawtv / tvtime,
etc. will prefer packed pixel formats. But when using a video card which
is using xf86-video-modesetting + glamor, only planar XVideo fmts are
available, and xawtv will chose a matching capture format to avoid needing
to do conversion, triggering the solid green window problem.

Signed-off-by: Hans de Goede <hdegoede at redhat.com>
Acked-by: Hans Verkuil <hans.verkuil at cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab at osg.samsung.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/media/pci/bt8xx/bttv-driver.c | 26 ++++++++++++++++++++------
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/drivers/media/pci/bt8xx/bttv-driver.c b/drivers/media/pci/bt8xx/bttv-driver.c
index 3632958..06d586b 100644
--- a/drivers/media/pci/bt8xx/bttv-driver.c
+++ b/drivers/media/pci/bt8xx/bttv-driver.c
@@ -2334,6 +2334,19 @@ static int bttv_g_fmt_vid_overlay(struct file *file, void *priv,
 	return 0;
 }

+static void bttv_get_width_mask_vid_cap(const struct bttv_format *fmt,
+					unsigned int *width_mask,
+					unsigned int *width_bias)
+{
+	if (fmt->flags & FORMAT_FLAGS_PLANAR) {
+		*width_mask = ~15; /* width must be a multiple of 16 pixels */
+		*width_bias = 8;   /* nearest */
+	} else {
+		*width_mask = ~3; /* width must be a multiple of 4 pixels */
+		*width_bias = 2;  /* nearest */
+	}
+}
+
 static int bttv_try_fmt_vid_cap(struct file *file, void *priv,
 						struct v4l2_format *f)
 {
@@ -2343,6 +2356,7 @@ static int bttv_try_fmt_vid_cap(struct file *file, void *priv,
 	enum v4l2_field field;
 	__s32 width, height;
 	__s32 height2;
+	unsigned int width_mask, width_bias;
 	int rc;

 	fmt = format_by_fourcc(f->fmt.pix.pixelformat);
@@ -2375,9 +2389,9 @@ static int bttv_try_fmt_vid_cap(struct file *file, void *priv,
 	width = f->fmt.pix.width;
 	height = f->fmt.pix.height;

+	bttv_get_width_mask_vid_cap(fmt, &width_mask, &width_bias);
 	rc = limit_scaled_size_lock(fh, &width, &height, field,
-			       /* width_mask: 4 pixels */ ~3,
-			       /* width_bias: nearest */ 2,
+			       width_mask, width_bias,
 			       /* adjust_size */ 1,
 			       /* adjust_crop */ 0);
 	if (0 != rc)
@@ -2410,6 +2424,7 @@ static int bttv_s_fmt_vid_cap(struct file *file, void *priv,
 	struct bttv_fh *fh = priv;
 	struct bttv *btv = fh->btv;
 	__s32 width, height;
+	unsigned int width_mask, width_bias;
 	enum v4l2_field field;

 	retval = bttv_switch_type(fh, f->type);
@@ -2424,9 +2439,10 @@ static int bttv_s_fmt_vid_cap(struct file *file, void *priv,
 	height = f->fmt.pix.height;
 	field = f->fmt.pix.field;

+	fmt = format_by_fourcc(f->fmt.pix.pixelformat);
+	bttv_get_width_mask_vid_cap(fmt, &width_mask, &width_bias);
 	retval = limit_scaled_size_lock(fh, &width, &height, f->fmt.pix.field,
-			       /* width_mask: 4 pixels */ ~3,
-			       /* width_bias: nearest */ 2,
+			       width_mask, width_bias,
 			       /* adjust_size */ 1,
 			       /* adjust_crop */ 1);
 	if (0 != retval)
@@ -2434,8 +2450,6 @@ static int bttv_s_fmt_vid_cap(struct file *file, void *priv,

 	f->fmt.pix.field = field;

-	fmt = format_by_fourcc(f->fmt.pix.pixelformat);
-
 	/* update our state informations */
 	fh->fmt              = fmt;
 	fh->cap.field        = f->fmt.pix.field;
--
2.7.4