From: Dan Streetman Subject: Re: crypto/nx842: Ignore queue overflow informative error Date: Mon, 7 Dec 2015 14:39:22 -0500 Message-ID: References: <1449388004.2096.12.camel@hbabu-laptop> <87bna36v91.fsf@gamma.ozlabs.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: Haren Myneni , Herbert Xu , "David S. Miller" , Michael Ellerman , pair@us.ibm.com, Linux Crypto Mailing List , linux-kernel , "linuxppc-dev@lists.ozlabs.org" To: Daniel Axtens Return-path: In-Reply-To: <87bna36v91.fsf@gamma.ozlabs.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org On Sun, Dec 6, 2015 at 5:57 PM, Daniel Axtens wrote: > Haren Myneni writes: > >> NX842 coprocessor sets bit 3 if queue is overflow. It is just for >> information to the user. So the driver prints this informative message >> and ignores it. > > What queue, and what happens when the queue overflows? It seems like > *something* would need to be done, somewhere, by someone? > > I realise that as a piece of IBM hardware this is probably an incredibly > optimistic question, but is this behaviour documented publically anywhere? > (As a distant second best, is it documented internally anywhere that I > can read?) When I worked there, it unfortunately wasn't public and there was no future plan to make it public, but things might have changed since I left. Maybe it will be included in future openpower documentation...? > >> --- a/drivers/crypto/nx/nx-842-powernv.c >> +++ b/drivers/crypto/nx/nx-842-powernv.c >> @@ -442,6 +442,15 @@ static int nx842_powernv_function(const unsigned char *in, unsigned int inlen, >> (unsigned int)ccw, >> (unsigned int)be32_to_cpu(crb->ccw)); >> >> + /* >> + * NX842 coprocessor uses 3rd bit to report queue overflow which is >> + * not an error, just for information to user. So, ignore this bit. >> + */ >> + if (ret & ICSWX_BIT3) { >> + pr_info_ratelimited("842 coprocessor queue overflow\n"); > It doesn't look like this is done anywhere else in the file, but should > this be prefixed with something? Something like "nx-842: Coprocessor > queue overflow"? it defines pr_fmt at the top of the file so it will be prefixed with the module name. > > Regards, > Daniel > >> + ret &= ~ICSWX_BIT3; >> + } >> + >> switch (ret) { >> case ICSWX_INITIATED: >> ret = wait_for_csb(wmem, csb); >> >> >> _______________________________________________ >> Linuxppc-dev mailing list >> Linuxppc-dev@lists.ozlabs.org >> https://lists.ozlabs.org/listinfo/linuxppc-dev