[U-Boot-Users] CPM on 8250 board seems stuck.

[Wolfgang Denk]

In message <F0C0133D6BE53342B2A78DE5D200E0A0074577 at ssmail2.corp.skystream.com> you wrote:
> 
> When I step through the code using BDI, I see is the code is stuck in a
> while 
> loop in serial_putc waiting for the Buffer descriptor ready bit to get
> cleared 
> in putc function.
> 
>        while ( tbdf->cbd_sc & BD_SC_READY )
> 		;
...
> It appears to me that CPM is "dead". Now how do I prove things either way,
> that it is not dead or its is working. Any CLUES I would really appreciate
> them.

Most probably the CPM is _not_ dead.

This is a typical case where you should lean back and think about the
problem. So you programmed an UART, and wait for it to complete send-
ing a character. When will this complete? After the last bit and  the
stop  bit(s)  have  been  clocked out. How long will this take? Well,
this obviously depends on the  clock.  Why  might  it  hang  forever?
Ummm... Maybe there is no clock???

Maybe there is no clock???

Check your BRG setup (probably OK, since not  board  dependent),  and
double-check your clock routing!


> Anybody here that has done 8250 board, and booted u-boot on it, care to
> share your 
> config.h file?

Why don't you just use  one  of  the  files  in  the  include/configs
directory?  Checking  for example the MAINTAINERS file will reveal at
least two MPC8250 based boards.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
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