Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757433AbZINWTN (ORCPT ); Mon, 14 Sep 2009 18:19:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756794AbZINWTN (ORCPT ); Mon, 14 Sep 2009 18:19:13 -0400 Received: from smtp-out.google.com ([216.239.45.13]:37656 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757318AbZINWTM (ORCPT ); Mon, 14 Sep 2009 18:19:12 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=mime-version:in-reply-to:references:date:message-id:subject:from:to: cc:content-type:x-system-of-record; b=LtEYrSrn6HP+DGAt4F+zOOot1pNrofsBJdjCqLu3symULIzg4oQ+ncYekeQfb2RyW 9Chk7ecClahvrV4KI4K3w== MIME-Version: 1.0 In-Reply-To: <1252965980.11643.261.camel@desktop> References: <20090914215855.GC11667@elf.ucw.cz> <1252965980.11643.261.camel@desktop> Date: Mon, 14 Sep 2009 15:19:11 -0700 Message-ID: Subject: Re: [patch 3/6] add pmem driver From: Brian Swetland To: Daniel Walker Cc: Pavel Machek , Greg KH , arve@android.com, kernel list , Iliyan Malchev , Petri Gynther Content-Type: text/plain; charset=UTF-8 X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1395 Lines: 31 On Mon, Sep 14, 2009 at 3:06 PM, Daniel Walker wrote: > On Mon, 2009-09-14 at 23:58 +0200, Pavel Machek wrote: >> >> This adds android pmem driver, one of dependencies of camera driver. > > I wouldn't even both with this one .. There's no way it could ever go > into mainline .. According to the android developers the camera , and > the frame buffer driver should work without it anyway.. The latest camera driver should work without pmem (or be fixable to do so -- I forget if that's done yet). The framebuffer itself does not need pmem, but pmem is used heavily by the android userspace on dream/magic for hardware compositable surfaces (since the 2d compositor requires physically contiguous memory). Is there a general linux kernel solution for managing large (1-8MB+) chunks of physically contiguous memory that needs to be shared between kernel and userspace for media operations? This is a very common problem with these SoCs -- the a/v subsystem and/or GPU don't have scatter/gather or MMU support and as a result we need to carve out memory for their use and provide some way for userspace to manipulate it. Brian -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/