On Thu, 21 Mar 2013 03:12:54 -0400 Akshay Saraswat akshay.s@samsung.com wrote:
On Mon, 18 Mar 2013 02:06:15 -0400 Akshay Saraswat akshay.s@samsung.com wrote:
- while ((readl(&ace_sha_reg->hash_status) & ACE_HASH_MSGDONE_MASK) ==
ACE_HASH_MSGDONE_OFF) {/** PRNG error bit goes HIGH if a PRNG request occurs without* a complete seed setup. We are using this bit to check h/w* because proper setup is not expected in that case.*/if ((readl(&ace_sha_reg->hash_status)& ACE_HASH_PRNGERROR_MASK) == ACE_HASH_PRNGERROR_ON)break;- }
so we have:
whilst (not_done) if (PRNGERROR_ON) break;
...and then success-assuming code flow continues after this. What value is this check for PRNGERROR_ON, if the code isn't going to do anything differently? And what does the status of the RNG have to do with keyless hashing? It sounds like a check for proper initialization (RNG got seeded) is in order here, but only if it's required for the given hash operations (I doubt it, but the h/w might be fussy).
PRNG ERROR means setup was not proper which should be the case when h/w is faulty because driver does everything in order.
The comment above says:
"PRNG error bit goes HIGH if a PRNG request occurs without a complete seed setup"
But a SHA request isn't a PRNG request. The h/w shouldn't need the PRNG at all to perform a simple SHA.
If this is a general initialization/"setup" check, then do it then. If not, can you do it immediately prior to the wait-for-done after the "setup"? A PRNG error shouldn't be going off in the middle of the wait-for-done loop for a SHA.
Earlier break was happening which was not correct so changing it to "return -EBUSY" which means code flow should not be the same as the one being successfull.
-EBUSY? that means the h/w was busy, and carries a "try again" implication (much like -EAGAIN) - I doubt that's what's intended here.
What happened to reverting to s/w, btw?
Kim