[PATCH v3 02/10] crypto: marvell: Check engine is not already running when enabling a req

[Romain Perier]

Hello,

Le 22/06/2016 12:33, Herbert Xu a écrit :
> Romain Perier <romain.perier at free-electrons.com> wrote:
>> Add a BUG_ON() call when the driver tries to launch a crypto request
>> while the engine is still processing the previous one. This replaces
>> a silent system hang by a verbose kernel panic with the associated
>> backtrace to let the user know that something went wrong in the CESA
>> driver.
>
> Hmm, so how can this happen?
If it is triggerable then we better
> try to recover from it more gracefully.  If it is not triggerable
> then why bother?
>

Well, It does not happen with the current driver (in mainline). This is 
bug I had when I added support to chain requests. Take a look at the 
patch 008/010, it changes the way the requests are "prepared". If you 
really enable a request while the engine is running, that's very hard to 
debug. This is more useful to have a backtrace to let the user know that 
something is wrong instead of having a silent system hang. That's easier 
to debug and you can detect regressions.

Regards,
Romain
-- 
Romain Perier, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com