wpaul 9617128953 Fix some stability problems:
- Normally, the driver allocates an mbuf cluster for each receive
  descriptor. This is because we have to be prepared to accomodate up to
  1500 bytes (a cluster buffer can hold up to 2K). However, using up a
  whole cluster buffer for a tiny packet is a bit of a waste. Also,
  it seems to me that sometimes mbufs will linger in the kernel for
  a while after being passed out of the driver, which means we might
  drain the mbuf cluster pool. The cluster pool is smaller than the
  mbuf pool in general, so we do the following: if the packet is less
  that MINCLSIZE bytes, then we copy it into a small mbuf chain and
  leave the mbuf cluster in place for another go-round. This saves
  mbuf clusters in some cases while still allowing them to be used
  for heavy traffic exchanges with lots of full-sized frames.

- The transmit descriptor has a bit in the control word which allows
  the driver to request that a 'TX OK' interrupt be generated when
  a frame has been completed. Sometimes, a frame can be fragmented
  across several descriptors. The manual for the real DEC 21140A says
  that if this happens, the 'TX interrupt request' bit is only valid
  in the descriptor of the last fragment. With the ASIX chip, it seems
  the 'TX interrupt request' bit is only valid in the descriptor of
  the _first_ fragment. Actually, the manual contains conflicting
  information, but I think it's supposed to be the first fragment.
  To play it safe, set the bit in both the first and last fragment to
  be sure that we get a TX OK interrupt. Without this fix, the driver
  can sometimes be late in releasing mbufs from the transmit queue
  after transmission.
1999-01-16 06:19:38 +00:00
..
1998-12-15 08:24:45 +00:00
1998-06-13 17:20:03 +00:00
1999-01-16 03:55:46 +00:00
1999-01-16 06:19:38 +00:00
1998-12-30 00:37:44 +00:00
1998-10-22 15:52:25 +00:00
1998-12-30 00:37:44 +00:00
1998-09-15 08:21:13 +00:00
1998-10-07 03:40:51 +00:00
1999-01-12 01:42:43 +00:00

-------------------------------------------------------------------------------
Recent versions of 3.0-current have the bktr driver built in.  Older versions
of 3.0 and all versions of 2.2 need to have the driver files installed by hand:

cp ioctl_bt848.h /sys/i386/include/
cp brktree_reg.h brooktree848.c /sys/pci/

In /sys/conf/files add:
pci/brooktree848.c        optional bktr device-driver

-------------------------------------------------------------------------------
In all cases you will need to add the driver to your kernel:

In your kernel configuration file:
controller      pci0     #if you already have this line don't add it.
device          bktr0    

There is no need to specify DMA channels nor interrupts for this
driver.

-------------------------------------------------------------------------------
Finally you need to create nodes for the driver:

Create a video device:
mknod /dev/bktr0 c 92 0

Create a tuner device:
mknod /dev/tuner0 c 92 16

-------------------------------------------------------------------------------
The code attempts to auto-probe code to detect card/tuner types.
The detected card is printed in the dmesg as the driver is loaded.  If
this fails to detect the proper card you can override it in brooktree848.c:

#define OVERRIDE_CARD	<card type>

where <card type> is one of:
	CARD_UNKNOWN
	CARD_MIRO
	CARD_HAUPPAUGE
	CARD_STB
	CARD_INTEL

-------------------------------------------------------------------------------
This model now separates the "tuner control" items into a minor device:

minor device layout:  xxxxxxxx xxxT UUUU

 UUUU:   the card (ie UNIT) identifier, 0 thru 15
 T == 0: video device
 T == 1: tuner device

Access your tuner ioctl thru your tuner device handle and anything
which controls the video capture process thru the video device handle.

Certain ioctl()s such as video source are available thru both devices.

-------------------------------------------------------------------------------
If your tuner does not work properly or is not recognized properly
try setting the tuner type via or card type:
sysctl -w hw.bt848.card=<integer> current valid values are 0 to 5 inclusive
sysctl -w hw.bt848.tuner=<integer> where integer is a value from 1 to 10
systcl -w hw.bt848.reverse_mute=<1 | 0> to reverse the mute function in the
                                driver set variable to 1.
The exact format of the sysctl bt848 variable is:
unit << 8 | value

unit identifies the pci bt848 board to be affected 0 is the first bt848 
board, 1 is the second bt848 board.
value denotes the integer value for tuners is a value from 0 to 10 for
reversing the mute function of the tuner the value is 1 or 0.

to find out all the bt848 variables:
sysctl hw.bt848



-------------------------------------------------------------------------------
The bt848 driver consists of:

src/sys/i386/include/ioctl_bt848.h
src/sys/pci/brktree_reg.h
src/sys/pci/brooktree848.c