linux-kernel - Re: [PATCH] crypto: caam: fix error reporting

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Message-ID: <54589515.2010903@freescale.com>
Date:	Tue, 4 Nov 2014 10:57:57 +0200
From:	Cristian Stoica <cristian.stoica@...escale.com>
To:	Kim Phillips <kim.phillips@...escale.com>
CC:	<herbert@...dor.apana.org.au>, <davem@...emloft.net>,
	<linux-crypto@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	<horia.geanta@...escale.com>, <marex@...x.de>
Subject: Re: [PATCH] crypto: caam: fix error reporting

Hi Kim,

>> Actually, our static code analyzer did not see this one.
> 
> ok, so the patch technically isn't fixing anything broken, then.

Are you saying the code isn't broken _because_ a static tool analyser
did not see anything wrong here?


> the new code just added a new condition, which doesn't invalidate
> the comment.  And simply removing the comment as opposed to amending
> it is a bit overkill.

You are partially right, but will the staggering lack of comments in the
caam driver be fixed by duplicating a cascade of three ifs into english?


>> It is indeed simpler but does it consider also the missing error codes
>> at index 1 and 5? Just checking for an upper bound is not enough.
>
> no, the existing code already handles that.  Note that newer
> documentation fills the 1 and 5 slots, too.

If you have the new error codes please send them to me for an update.


>> On the other hand, if the error field is only three bits wide instead of
>> four as stated by the documentation, a better fix means using a three
>> bit mask instead of reporting an invalid error code.
> 
> true, but then we'd introduce a direct discrepancy with the
> documentation, and thus h/w.

You basically ask me to agree that if there are no _documented_ error
codes between 0x8 and 0xf then I should trust that they will never come
up on a 4 bit field.

Do you want me to drop the patch and pretend there is nothing to see?


Cristian S.
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