[PATCH 3/7] ARM i.MX6q: Add GPU, VPU, IPU, and OpenVG resets to System Reset Controller (SRC)

On Mon, Jan 21, 2013 at 11:47:12AM -0600, Matt Sealey wrote:

quoted

Yes, maybe the module reset part of the SRC should be implemented as a
proper device driver in drivers/reset. Then we could use the interrupt
functionality and WARN_ON(timeout), as you suggest.

That would be ideal. Maybe Shawn or Fabio can bug a hardware guy to
shed some light on what a reasonable timeout might actually be for a
module to cause such a warning. I think it should definitely cause
one.. as I said, I was using 5 seconds, you used 1 second, I don't
think a shorter delay would be unreasonable, but maybe it could take
up to 10 seconds, or maybe I am wrong - maybe it is in fact impossible
in hardware for a reset to "fail" at least visibly because the
interrupt will always fire making the warning a never-traveled path.
It is certainly not something that would be documented, so without a
view of the RTL logic here, we wouldn't know.

Shawn, Fabio?

Just talked to hardware people, the reset should finish in a few
clock cycles, so even 1 millisecond should be enough.

Shawn