From: Romain Perier <romain.perier@free-electrons.com>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: thomas.petazzoni@free-electrons.com,
boris.brezillon@free-electrons.com, linux@arm.linux.org.uk,
arno@natisbad.org, linux-crypto@vger.kernel.org,
gregory.clement@free-electrons.com, davem@davemloft.net,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v3 02/10] crypto: marvell: Check engine is not already running when enabling a req
Date: Wed, 22 Jun 2016 13:23:39 +0200 [thread overview]
Message-ID: <576A753B.7070507@free-electrons.com> (raw)
In-Reply-To: <20160622103324.GA30918@gondor.apana.org.au>
Hello,
Le 22/06/2016 12:33, Herbert Xu a écrit :
> Romain Perier <romain.perier@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
next prev parent reply other threads:[~2016-06-22 11:23 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-21 8:08 [PATCH v3 00/10] Chain crypto requests together at the DMA level Romain Perier
2016-06-21 8:08 ` [PATCH v3 01/10] crypto: marvell: Add a macro constant for the size of the crypto queue Romain Perier
2016-06-21 8:08 ` [PATCH v3 02/10] crypto: marvell: Check engine is not already running when enabling a req Romain Perier
2016-06-22 10:33 ` Herbert Xu
2016-06-22 11:23 ` Romain Perier [this message]
2016-06-23 10:44 ` Herbert Xu
2016-06-21 8:08 ` [PATCH v3 03/10] crypto: marvell: Fix wrong type check in dma functions Romain Perier
2016-06-21 8:08 ` [PATCH v3 04/10] crypto: marvell: Copy IV vectors by DMA transfers for acipher requests Romain Perier
2016-06-21 8:08 ` [PATCH v3 05/10] crypto: marvell: Move tdma chain out of mv_cesa_tdma_req and remove it Romain Perier
2016-06-21 8:08 ` [PATCH v3 06/10] crypto: marvell: Add a complete operation for async requests Romain Perier
2016-06-21 8:08 ` [PATCH v3 07/10] crypto: marvell: Move SRAM I/O operations to step functions Romain Perier
2016-06-21 8:08 ` [PATCH v3 08/10] crypto: marvell: Add load balancing between engines Romain Perier
2016-06-21 12:33 ` Boris Brezillon
2016-06-21 8:08 ` [PATCH v3 09/10] crypto: marvell: Add support for chaining crypto requests in TDMA mode Romain Perier
2016-06-21 12:37 ` Boris Brezillon
2016-06-21 8:08 ` [PATCH v3 10/10] crypto: marvell: Increase the size of the crypto queue Romain Perier
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