[U-Boot] slow flash write with Freescale P1020 and PC28F256J3 NOR-flash

I am bringing up a board that has a Freescale P1020 (PowerPC e500v2) and a 16-bit PC28F256J3 NOR-flash on it.

My problem is that both erases and programming takes very long time. Reading from the flash on the other hand, is quite fast (at least a few MByte/s).

I have set up the BR0, OR0 and other GPCM-related parameters to be as fast as the datasheet allows.

To give an example of how slow it is, programming 24MiB data takes around 45 minutes. Erasing the area before programming takes 2-3 minutes.

I have based my project on a 2011.09 version of u-boot.

Is there any known limitation, problem or workaround?

Regards Daniel Nilsson