[U-Boot] Problems with a P2020 board

[Mark Marshall]

Hi.

We have a new board which we are suing with U-boot.  The CPU is a P2020.
I am having a  few minor problems, and I was hoping to get some help.

-       Boot Count.  We are keen to use the boot counter feature, but I
am struggling to find a suitable register in the P2020.  The file
arch/powerpc/lib/bootcount.c list a few locations that work with
other PowerPC chips, but I can't find any of those registers in the
P2020 documentation.

-       SPI Flash seems very slow.  The SPI flash accesses all seem to be very
slow.  I can increase the SPI clock (to 40 MHz) and this helps, but the
real problem is the code in drivers/spi/fsl_espi.c.  Here there is an 80us
delay after each 32-bit value is written to the TX FIFO.  I don't understand
why this delay is there?  If I reduce it to 2 usec everything still works, and
SPI Flash accesses are much faster.  I can easily produce a patch to
remove or reduce this delay, but I'd rather know why it was there in the
first place?

-       Timer Interrupts seem to stop.  Once U-boot has started the timer
interrupts seem to stop.  I have added a test command that prints out
the timestamp variable (from arch/powerpc/lib/interrupts.c).  I can
see that when we enter the interactive loop this variable stops
incrementing.  I can add boot scripts that output this value, and it
is incrementing until the console becomes interactive.  Has anyone
else seen a problem like this?

Many thanks for any help you can offer us.

Mark Marshall.