[sane-devel] problem resetting register

[Parag N(पराग़)]

Hello,
        This is with reference to my previous mails for Hp 2400
genesys backend development. what i am getting is that after 1755
lines head moves other end and instead of moving back it tries to move
furhter. genesys code calulates that head has to scan 3510 lines which
must be actually 1755 lines. so i modified code so that to reset head
to move back after 1755 lines scanned. but besides i am writing to
0x02 register 53 decimal value it scanning further after 1755 and
after lines count drop to 0 head automatically resets to home by
moving backwards. code is included in sane_read in genesys.c
heres the whole modified function

SANE_Status
sane_read (SANE_Handle handle, SANE_Byte * buf, SANE_Int max_len,
           SANE_Int * len)
{
  Genesys_Scanner *s = handle;
  SANE_Status status;
  size_t local_len;
unsigned int channels,depth,lines;
  if (!s)
    {
      DBG (DBG_error, "sane_read: handle is null!\n");
      return SANE_STATUS_INVAL;
    }

  if (!buf)
    {
      DBG (DBG_error, "sane_read: buf is null!\n");
      return SANE_STATUS_INVAL;
    }

  if (!len)
    {
      DBG (DBG_error, "sane_read: len is null!\n");
      return SANE_STATUS_INVAL;
    }

  *len = 0;

  if (!s->scanning)
    {
      DBG (DBG_warn, "sane_read: scan was cancelled, is over or has not been "
           "initiated yet\n");
      return SANE_STATUS_CANCELLED;
    }

  DBG (DBG_proc, "sane_read: start\n");
  channels = s->dev->current_setup.channels;
  depth = s->dev->current_setup.depth;
  lines=(((s->dev->total_bytes_to_read - s->dev->total_bytes_read)*8)/
          (s->dev->settings.pixels*channels*depth));

  DBG (DBG_info, "genesys_sane_read: %d lines left by output\n",lines);
 if(lines==(lines/2))
{
 status =sanei_genesys_write_register (s->dev, 0x02, 53);
  if (status != SANE_STATUS_GOOD)
    {
      DBG (DBG_error,
           "sanei_genesys_fe_write_data: Failed while bulk writing
registers: %s\n",
           sane_strstatus (status));
    return status;
    }
}
  local_len = max_len;
  status = genesys_read_ordered_data (s->dev, buf, &local_len);

  *len = local_len;
  return status;
}

Can anybody point out where the things are going wrong?
Thanks & regards,
Parag.