writing to mac,bbp or rf registers not supported?

[Marcelo Tosatti]

On Thu, Nov 30, 2006 at 04:08:50PM -0200, Marcelo Tosatti wrote:
> 
> On Wed, Nov 29, 2006 at 05:05:33AM -0800, Ronak Chokshi wrote:
> > Marcelo,
> > Have you tried writing to any other MAC, BBP, RF register? What are the
> > other registers that you have tried writing?
> 
> Ronak,
> 
> I've only tried these three. As far as I can tell there is no support
> for any other register access.
> 
> There are some offsets of the BBP register which retain written values
> (don't recall which offset, board is temporarily unavailable).
> 
> Were written values to MAC register supposed to be retained?
> 
> One point here is that the meaning of these registers is not documented
> anywhere, which is unfortunate (ie. no one except Marvell can easily
> understand whats going on).
> 
> These issues were present before, and this is a rather specialized
> debugging feature, so I don't consider it high priority, but still.

More info...

Only certain bits from certain offsets are retained:

-bash-3.1# pwd
/mnt/libertas_wireless/eth0/registers
-bash-3.1# echo "0x4" > rdrf ; cat rdrf
RF[0x4] = 0x00000000

(default value for 0x4 offset)

-bash-3.1# echo "0x4 0xffffffff" > wrrf
-bash-3.1# echo 0x4 > rdrf ; cat rdrf
RF[0x4] = 0x00000007
-bash-3.1#

Only the three first bits are writable.

While 0x0 offset seems read-only:

bash-3.1# echo 0 > rdrf ; cat rdrf
RF[0x0] = 0x00000005
-bash-3.1# echo "0x0 0xffffffff" > wrrf
-bash-3.1# echo 0 > rdrf ; cat rdrf
RF[0x0] = 0x00000005
-bash-3.1#

While others vary:

-bash-3.1# echo 0x8 > rdbbp ; cat rdbbp
BBP[0x8] = 0x00000003
-bash-3.1# cat rdbbp
BBP[0x8] = 0x00000003
-bash-3.1# cat rdbbp
BBP[0x8] = 0x0000000b
-bash-3.1# cat rdbbp
BBP[0x8] = 0x00000003
-bash-3.1# cat rdbbp
BBP[0x8] = 0x00000003
-bash-3.1# cat rdbbp
BBP[0x8] = 0x00000003
-bash-3.1# cat rdbbp
BBP[0x8] = 0x00000003
-bash-3.1# cat rdbbp
BBP[0x8] = 0x00000003
-bash-3.1# cat rdbbp
BBP[0x8] = 0x00000003
-bash-3.1# cat rdbbp
BBP[0x8] = 0x0000000b
-bash-3.1# cat rdbbp
BBP[0x8] = 0x00000003

So basically the current situation is that we have no clue on the
content of these registers. Is there documentation for that available?

Thanks