From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-f177.google.com (mail-ob0-f177.google.com [209.85.214.177]) by kanga.kvack.org (Postfix) with ESMTP id 0120F6B0038 for ; Mon, 12 May 2014 05:42:42 -0400 (EDT) Received: by mail-ob0-f177.google.com with SMTP id gq1so7589982obb.36 for ; Mon, 12 May 2014 02:42:42 -0700 (PDT) Received: from bay0-omc3-s21.bay0.hotmail.com (bay0-omc3-s21.bay0.hotmail.com. [65.54.190.159]) by mx.google.com with ESMTP id db3si6052640pbc.273.2014.05.12.02.42.42 for ; Mon, 12 May 2014 02:42:42 -0700 (PDT) Message-ID: From: Pintu Kumar Subject: Questions regarding DMA buffer sharing using IOMMU Date: Mon, 12 May 2014 15:12:41 +0530 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: "linux-mm@kvack.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "linaro-mm-sig@lists.linaro.org" Hi=2C=A0=0A= I have some queries regarding IOMMU and CMA buffer sharing.=A0=0A= We have an embedded linux device (kernel 3.10=2C RAM: 256Mb) in which camer= a and codec supports IOMMU but the display does not support IOMMU.=A0=0A= Thus for camera capture we are using iommu buffers using ION/DMABUF. But fo= r all display rendering we are using CMA buffers.=A0=0A= So=2C the question is how to achieve buffer sharing (zero-copy) between Cam= era and Display using only IOMMU?=A0=0A= Currently we are achieving zero-copy using CMA. And we are exploring option= s to use IOMMU.=A0=0A= Now we wanted to know which option is better? To use IOMMU or CMA?=A0=0A= If anybody have come across these design please share your thoughts and res= ults.=A0=0A= =0A= =0A= Thank You!=A0=0A= Regards=2C=A0=0A= Pintu=0A= =0A= = -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org