CPM2 (MPC8260) SMC problem. Please help.

[Vitaly Bordug]

On Wed, 18 Oct 2006 22:40:31 +0200
Boris Shteinbock <boris at fabiotec.com> wrote:

> Hi ppl.
> 
> I have discovered very very odd problem with SMC2 on my 8260 board.
> kernel version is 2.6.17.
> 
> The board is 8260 with serial ports on SMC1 and SMC 2 (SMC1 - console)
> 
> Now if I use SMC2 for communicating with remote device, ( some protocol)
> I am sending packets and wait for a response.
> However if the packet I send is SMALLER than 5 bytes, SMC goes 
> completely crazy.
> write() doesn't return error, but the next read() hangs completely, and the
> process moves to D state and it is impossible to kill it by any means.
> It only happens when consequent writes of smaller than 5 bytes.
> I tried to check the driver, but couldn't find any clues to what goes wrong.
> 
> I tried both compatibility and platform-based modes with the same results.
> 
> Any help on the issue would be highliy appreciated.
> 
> 

I think that should be walked along the cpm_uart driver, TX part to see is sending stuff 
do not indicate any error in the CPM registers, or at least discover exact track leading to the endless loop. 

-- 
Sincerely, 
Vitaly