From: Herbert Xu Subject: Re: [PATCH 1/1] crypto: omap-sham: Adjust DMA parameters Date: Fri, 3 Sep 2010 19:20:52 +0800 Message-ID: <20100903112052.GD31881@gondor.apana.org.au> References: <018d83bcce6fea623a9c7d19b3739ec7b54610c5.1283436919.git.dmitry.kasatkin@nokia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-crypto@vger.kernel.org, linux-omap@vger.kernel.org, Samu Onkalo To: Dmitry Kasatkin Return-path: Received: from helcar.apana.org.au ([209.40.204.226]:47989 "EHLO fornost.hengli.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756560Ab0ICLUz (ORCPT ); Fri, 3 Sep 2010 07:20:55 -0400 Content-Disposition: inline In-Reply-To: <018d83bcce6fea623a9c7d19b3739ec7b54610c5.1283436919.git.dmitry.kasatkin@nokia.com> Sender: linux-crypto-owner@vger.kernel.org List-ID: On Thu, Sep 02, 2010 at 05:17:35PM +0300, Dmitry Kasatkin wrote: > From: Samu Onkalo > > DMA is set to use burst mode also for source channel. It should > descrease memory bandwidth needs. > > DMA synchronization is set to use prefetch mechanism. SHAM block is behind > L4 bus and it doesn't have fifo. SHAM block is stalling as long as the new > data is available. It takes time to fetch data from memory and transfer it > via L4 bus. With prefetch enabled, data is waiting in DMA fifo and SHAM block > receives new data block faster. > This increases SHA processing speed up to 30 percent depending on the > bus / memory load. > > Signed-off-by: Samu Onkalo > Signed-off-by: Dmitry Kasatkin Patch applied. Thanks! -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt