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

Hello,

Le 22/06/2016 12:33, Herbert Xu a écrit :

Romain Perier [off-list ref] wrote:

quoted

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