V4L/DVB (11913): cx231xx: TRY_FMT should not actually set anything

In the TRY_FMT handler the function get_scale() is called to find what the
scaler hardware will produce for a requested size.

The problem is that get_scale(struct cx231xx *dev, ..., unsigned int *vscale,
unsigned int *hscale) saves the calculated scale values into both the
pointer arguments and into dev's hscale and vscale fields.  TRY_FMT shouldn't
actually change anything in the device state.

The code to in get_scale() that writes to dev->[hv]scale can just be
deleted.  In all cases when dev's fields should be modified, get_scale()
was called with get_scale(dev, ..., &dev->hscale, &dev->vscale), so dev was
getting updated anyway.

This didn't actually cause a problem because nothing ever actually made use
of the hscale and vscale fields.  I changed cx231xx_resolution_set() to use
those fields rather than re-calculate them with a call to get_scale().

Updating [hv]scale in cx231xx_resolution_set() isn't necessary because
every call of cx231xx_resolution_set() was already preceded by a call to
get_scale() or setting the [hv]scale fields, so they will be always be
up-to-date w.r.t. width and height.

Removing the call to get_scale() from cx231xx_resolution_set() allowed
making get_scale() a static function, which is a good thing for something
with such a short name.  There is already another function with the same
name in the em28xx driver, but that one is static.

Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 3 insertions, 7 deletions

diff --git a/drivers/media/video/cx231xx/cx231xx-video.c b/drivers/media/video/cx231xx/cx231xx-video.c
index 6a524d847110..609bae6098d3 100644
--- a/drivers/media/video/cx231xx/cx231xx-video.c
+++ b/drivers/media/video/cx231xx/cx231xx-video.c
@@ -893,9 +893,9 @@ static int check_dev(struct cx231xx *dev)
         return 0;
 }
 
-void get_scale(struct cx231xx *dev,
-               unsigned int width, unsigned int height,
-               unsigned int *hscale, unsigned int *vscale)
+static void get_scale(struct cx231xx *dev,
+                      unsigned int width, unsigned int height,
+                      unsigned int *hscale, unsigned int *vscale)
 {
         unsigned int maxw = norm_maxw(dev);
         unsigned int maxh = norm_maxh(dev);
@@ -907,10 +907,6 @@ void get_scale(struct cx231xx *dev,
         *vscale = (((unsigned long)maxh) << 12) / height - 4096L;
         if (*vscale >= 0x4000)
                 *vscale = 0x3fff;
-
-        dev->hscale = *hscale;
-        dev->vscale = *vscale;
-
 }
 
 /* ------------------------------------------------------------------