From: Kumar Gala Subject: Re: [PATCH v2 2/2] Crypto: Talitos: Support for Async_tx XOR offload Date: Thu, 17 Dec 2009 11:29:26 -0600 Message-ID: References: <1260977698-4076-1-git-send-email-Vishnu@freescale.com> <20091216164144.daff5468.kim.phillips@freescale.com> <2868C8CF-584B-4FA7-9C3B-2FACEF77527E@kernel.crashing.org> <4B296394.9010709@intel.com> <20091217170958.GE18271@ovro.caltech.edu> Mime-Version: 1.0 (Apple Message framework v1077) Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: "herbert@gondor.apana.org.au" , "B04825@freescale.com" , "linux-kernel@vger.kernel.org" , "linux-raid@vger.kernel.org" , "linuxppc-dev@ozlabs.org" , Vishnu Suresh , "linux-crypto@vger.kernel.org" , Dipen Dudhat , Dan Williams , Maneesh Gupta , "R58472@freescale.com" To: "Ira W. Snyder" Return-path: In-Reply-To: <20091217170958.GE18271@ovro.caltech.edu> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linuxppc-dev-bounces+glppd-linuxppc64-dev=m.gmane.org@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+glppd-linuxppc64-dev=m.gmane.org@lists.ozlabs.org List-Id: linux-crypto.vger.kernel.org On Dec 17, 2009, at 11:09 AM, Ira W. Snyder wrote: > On Wed, Dec 16, 2009 at 03:47:48PM -0700, Dan Williams wrote: >> Kumar Gala wrote: >>>>> Changes with respect to v1 as per comments received >>>>> o. Rebased to linux-next as of 20091216 >>>>> o. The selection is based exclusive of fsldma >>>>> o. Intoduced a new Kernel Configuration variable >>>>> *. This enables selecting the Cryptographic functionality >>>>> of Talitos along with fsldma. >>>>> *. Disables the XOR parity calculation offload, if fsldma enabled >>>>> either as kernel in-built or as a module >>>>> *. Once the inter-operability with fsldma is resolved, this option >>>>> can be removed >>>> wait, why can't the interoperability bug be fixed in the first place? >>> >>> I agree w/Kim. We need to better understand what the bug is and how to reproduce it so we can get to the root cause. >>> >>> Paper taping over it by disabling fsldma is not the right solution. >> >> Hopefully this prompts fsldma authors to get involved because the >> interoperability issue has been out there without comment*, just >> band-aids, since October. >> >> -- >> Dan >> >> * well one comment from Ira saying the interrupt functionality worked >> for him. > > Yes, I have used the device_prep_dma_interrupt() functionality quite a > while back. However, I found it to be pretty much useless. Any > functionality I need is covered by adding a callback to the last DMA > memcpy() operation. Since the operations happen in-order, I can be sure > that the entire set of memcpy()s cas completed. I never needed the > capability to generate an interrupt without a memcpy(). > > I agree that the fsldma driver could use some love. There are places > where I am still not confident in the locking. Perhaps I can find some > time over Christmas to work on it, but I need someone with 85xx/86xx > hardware to test the changes. I only have 83xx hardware. I can test on 85xx/86xx if you work up some patches. - k