What is the recommended HPI initialization sequence for OMAP-L138?

In our project (custom board with OMAP-L138 and Spartan6) we have the following HPI initialization sequence (based on section 22.2.8 of OMAP-L138 DSP+ARM Processor Technical Reference Manual):

1. Configure HPI pinmux
2. Enable HPI in CFGCHIP1
3. Set DUALHPIA and HWOB in HPIC (done by FPGA connected to OMAP)
4. Configure FREE and SOFT bits in PWREMU_MGMT
5. Release HPI from reset
6. Verify that everything went correctly by checking if HWOB bit value changed (was written by FPGA)

Is this sequence correct? The problem is that we randomly (in about 4% cases) experience failure in step 6 (HWOB value is invalid) and we wonder if it's caused by some mistake in initialization sequence.