From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932633AbcJ3Ul7 (ORCPT ); Sun, 30 Oct 2016 16:41:59 -0400 Received: from mail-oi0-f65.google.com ([209.85.218.65]:33443 "EHLO mail-oi0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757517AbcJ3Ult (ORCPT ); Sun, 30 Oct 2016 16:41:49 -0400 Date: Sun, 30 Oct 2016 15:41:48 -0500 From: Rob Herring To: Niklas Cassel Cc: vinod.koul@intel.com, mark.rutland@arm.com, dan.j.williams@intel.com, dmaengine@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Niklas Cassel Subject: Re: [PATCH] dmaengine: nbpfaxi: add optional max-burst property for memory reads/writes Message-ID: <20161030204147.ysm6vsubfclae57y@rob-hp-laptop> References: <1477315755-4783-1-git-send-email-niklass@axis.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1477315755-4783-1-git-send-email-niklass@axis.com> User-Agent: Mutt/1.6.2-neo (2016-08-21) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 24, 2016 at 03:29:15PM +0200, Niklas Cassel wrote: > From: Niklas Cassel > > Due to a hardware bug, reading memory (from the Accelerator Coherency Port) > with a burst size equal to the maximum burst size allowed by the DMA > hardware's buffer size will cause a hardware hang on the ARTPEC-6 SoC, > where the only solution is a manual power cycle. > On ARTPEC-6, this hardware bug does not trigger when writing memory (to the > Accelerator Coherency Port) with a burst size equal to the maximum burst > size allowed by the DMA hardware's buffer size. > > To avoid this hardware hang, introduce a new optional max-burst property > for memory reads. For completeness, also introduce a max-burst property for > memory writes. > > Signed-off-by: Niklas Cassel > --- > Documentation/devicetree/bindings/dma/nbpfaxi.txt | 8 +++++ > drivers/dma/nbpfaxi.c | 38 ++++++++++++++++++++--- > 2 files changed, 42 insertions(+), 4 deletions(-) Acked-by: Rob Herring