From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [PATCH] dmaengine: nbpfaxi: add optional max-burst property for memory reads/writes Date: Sun, 30 Oct 2016 15:41:48 -0500 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 Return-path: Content-Disposition: inline In-Reply-To: <1477315755-4783-1-git-send-email-niklass-VrBV9hrLPhE@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Niklas Cassel Cc: vinod.koul-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, dmaengine-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Niklas Cassel List-Id: devicetree@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 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html