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[media] em28xx: clean up and unify functions em28xx_copy_vbi() em28xx_copy_video() 

The code in em28xx_vbi_copy can be simplified a lot.
Also rename some variables to something more meaningful and fix+add the
function descriptions.

Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Frank Schaefer 2012-12-08 11:31:32 -03:00 committed by Mauro Carvalho Chehab
parent 227b7c9067
commit 36016a351d
1 changed files with 21 additions and 46 deletions
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67
drivers/media/usb/em28xx/em28xx-video.c
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@ -168,28 +168,27 @@ static inline void finish_buffer(struct em28xx *dev,
}
/*
* Identify the buffer header type and properly handles
* Copy picture data from USB buffer to videobuf buffer
*/
static void em28xx_copy_video(struct em28xx *dev,
struct em28xx_buffer *buf,
unsigned char *p,
unsigned char *usb_buf,
unsigned long len)
{
void *fieldstart, *startwrite, *startread;
int linesdone, currlinedone, offset, lencopy, remain;
int bytesperline = dev->width << 1;
unsigned char *outp = buf->vb_buf;
if (buf->pos + len > buf->vb.size)
len = buf->vb.size - buf->pos;
startread = p;
startread = usb_buf;
remain = len;
if (dev->progressive || buf->top_field)
fieldstart = outp;
fieldstart = buf->vb_buf;
else /* interlaced mode, even nr. of lines */
fieldstart = outp + bytesperline;
fieldstart = buf->vb_buf + bytesperline;
linesdone = buf->pos / bytesperline;
currlinedone = buf->pos % bytesperline;
@ -203,11 +202,12 @@ static void em28xx_copy_video(struct em28xx *dev,
lencopy = bytesperline - currlinedone;
lencopy = lencopy > remain ? remain : lencopy;
if ((char *)startwrite + lencopy > (char *)outp + buf->vb.size) {
if ((char *)startwrite + lencopy > (char *)buf->vb_buf + buf->vb.size) {
em28xx_isocdbg("Overflow of %zi bytes past buffer end (1)\n",
((char *)startwrite + lencopy) -
((char *)outp + buf->vb.size));
remain = (char *)outp + buf->vb.size - (char *)startwrite;
((char *)startwrite + lencopy) -
((char *)buf->vb_buf + buf->vb.size));
remain = (char *)buf->vb_buf + buf->vb.size -
(char *)startwrite;
lencopy = remain;
}
if (lencopy <= 0)
@ -227,13 +227,13 @@ static void em28xx_copy_video(struct em28xx *dev,
else
lencopy = bytesperline;
if ((char *)startwrite + lencopy > (char *)outp +
if ((char *)startwrite + lencopy > (char *)buf->vb_buf +
buf->vb.size) {
em28xx_isocdbg("Overflow of %zi bytes past buffer end"
"(2)\n",
((char *)startwrite + lencopy) -
((char *)outp + buf->vb.size));
lencopy = remain = (char *)outp + buf->vb.size -
((char *)buf->vb_buf + buf->vb.size));
lencopy = remain = (char *)buf->vb_buf + buf->vb.size -
(char *)startwrite;
}
if (lencopy <= 0)
@ -247,50 +247,25 @@ static void em28xx_copy_video(struct em28xx *dev,
buf->pos += len;
}
/*
* Copy VBI data from USB buffer to videobuf buffer
*/
static void em28xx_copy_vbi(struct em28xx *dev,
struct em28xx_buffer *buf,
unsigned char *p,
unsigned char *usb_buf,
unsigned long len)
{
void *startwrite, *startread;
int offset;
int bytesperline;
unsigned char *outp;
if (dev == NULL) {
em28xx_isocdbg("dev is null\n");
return;
}
bytesperline = dev->vbi_width;
if (buf == NULL) {
return;
}
if (p == NULL) {
em28xx_isocdbg("p is null\n");
return;
}
outp = buf->vb_buf;
if (outp == NULL) {
em28xx_isocdbg("outp is null\n");
return;
}
unsigned int offset;
if (buf->pos + len > buf->vb.size)
len = buf->vb.size - buf->pos;
startread = p;
startwrite = outp + buf->pos;
offset = buf->pos;
/* Make sure the bottom field populates the second half of the frame */
if (buf->top_field == 0) {
startwrite += bytesperline * dev->vbi_height;
offset += bytesperline * dev->vbi_height;
}
if (buf->top_field == 0)
offset += dev->vbi_width * dev->vbi_height;
memcpy(startwrite, startread, len);
memcpy(buf->vb_buf + offset, usb_buf, len);
buf->pos += len;
}