Commit 1ca27379 authored by Trent Piepho's avatar Trent Piepho Committed by Mauro Carvalho Chehab
Browse files

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: default avatarTrent Piepho <>
Signed-off-by: default avatarMauro Carvalho Chehab <>
parent ccb83408
......@@ -1052,22 +1052,13 @@ int cx231xx_set_audio_decoder_input(struct cx231xx *dev,
/* Set resolution of the video */
int cx231xx_resolution_set(struct cx231xx *dev)
int width, height;
u32 hscale, vscale;
int status = 0;
width = dev->width;
height = dev->height;
get_scale(dev, width, height, &hscale, &vscale);
/* set horzontal scale */
status = vid_blk_write_word(dev, HSCALE_CTRL, hscale);
int status = vid_blk_write_word(dev, HSCALE_CTRL, dev->hscale);
if (status)
return status;
/* set vertical scale */
status = vid_blk_write_word(dev, VSCALE_CTRL, vscale);
return status;
return vid_blk_write_word(dev, VSCALE_CTRL, dev->vscale);
......@@ -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;
/* ------------------------------------------------------------------
......@@ -722,9 +722,6 @@ int cx231xx_set_video_input_mux(struct cx231xx *dev, u8 input);
int cx231xx_set_decoder_video_input(struct cx231xx *dev, u8 pin_type, u8 input);
int cx231xx_do_mode_ctrl_overrides(struct cx231xx *dev);
int cx231xx_set_audio_input(struct cx231xx *dev, u8 input);
void get_scale(struct cx231xx *dev,
unsigned int width, unsigned int height,
unsigned int *hscale, unsigned int *vscale);
/* Provided by cx231xx-video.c */
int cx231xx_register_extension(struct cx231xx_ops *dev);
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