Commit 34539b442b ("bus: ti-sysc: Flush posted write on enable before
reset") caused a regression reproducable on omap4 duovero where the ISS
target module can produce interconnect errors on boot. Turns out the
registers are not accessible until after a delay for devices needing
a ti,sysc-delay-us value.
Let's fix this by flushing the posted write only after the reset delay.
We do flushing also for ti,sysc-delay-us using devices as that should
trigger an interconnect error if the delay is not properly configured.
Let's also add some comments while at it.
Fixes: 34539b442b ("bus: ti-sysc: Flush posted write on enable before reset")
Cc: stable@vger.kernel.org
Signed-off-by: Tony Lindgren <tony@atomide.com>
f71f6ff8c1