From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754305Ab1LMPKR (ORCPT ); Tue, 13 Dec 2011 10:10:17 -0500 Received: from moutng.kundenserver.de ([212.227.126.187]:65277 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753212Ab1LMPKM (ORCPT ); Tue, 13 Dec 2011 10:10:12 -0500 From: Arnd Bergmann To: Robert Morell Subject: Re: [Linaro-mm-sig] [RFC v2 1/2] dma-buf: Introduce dma buffer sharing mechanism Date: Tue, 13 Dec 2011 15:10:02 +0000 User-Agent: KMail/1.12.2 (Linux/3.2.0-rc1+; KDE/4.3.2; x86_64; ; ) Cc: Mauro Carvalho Chehab , Sumit Semwal , "linux@arm.linux.org.uk" , "jesse.barker@linaro.org" , "linux-kernel@vger.kernel.org" , "dri-devel@lists.freedesktop.org" , "linaro-mm-sig@lists.linaro.org" , "linux-mm@kvack.org" , "daniel@ffwll.ch" , "linux-arm-kernel@lists.infradead.org" , "linux-media@vger.kernel.org" References: <1322816252-19955-1-git-send-email-sumit.semwal@ti.com> <4EE33EC2.6050508@redhat.com> <20111212224408.GD4355@morell.nvidia.com> In-Reply-To: <20111212224408.GD4355@morell.nvidia.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201112131510.02785.arnd@arndb.de> X-Provags-ID: V02:K0:KAnt+06/LdSLPqxJ/HGr27yMoV3PoRaP0iNUr8dEWrx qHNdkUoxrYOskTfxauUL/EriUMzGbduo46Ca/M3rAIzR5OwxYC Pbtr2uKYU3OQzxHhrRUXPNmcFhtJDXxsUzPzcCVukOkh3LrguU XfvB28/nb+0A6sSd60FkA5dlAWACoCjHFfYLJ/lp90vbPr5zzT xsPnakVUKPww+2OIO7hrsDi42ATgoivw4IliOYhYKoRXpagj8V rdnXvPq4VVDD52Hfp2qc2NN3oVr7u85+Xqg5z7AXrKVPjE9q2B GnTb4gXfICZv1thV/AITdSPzgwx+c8ahF8yZ9JbdqUuNbPOzEz eOPEubbEnsvWyfvyyzvw= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday 12 December 2011, Robert Morell wrote: > > > > Doing a buffer sharing with something that is not GPL is not fun, as, if any > > issue rises there, it would be impossible to discover if the problem is either > > at the closed-source driver or at the open source one. At the time I was using > > the Nvidia proprietary driver, it was very common to have unexplained issues > > caused likely by bad code there at the buffer management code, causing X > > applications and extensions (like xv) to break. > > > > We should really make this EXPORT_SYMBOL_GPL(), in order to be able to latter > > debug future share buffer issues, when needed. > > Sorry, I don't buy this argument. Making these exports GPL-only is not > likely to cause anybody to open-source their driver, but will rather > just cause them to use yet more closed-source code that is even less > debuggable than this would be, to those without access to the source. But at least the broken module then won't be interacting with other modules because it cannot share any buffers. Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from moutng.kundenserver.de ([212.227.126.187]:65277 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753212Ab1LMPKM (ORCPT ); Tue, 13 Dec 2011 10:10:12 -0500 From: Arnd Bergmann To: Robert Morell Subject: Re: [Linaro-mm-sig] [RFC v2 1/2] dma-buf: Introduce dma buffer sharing mechanism Date: Tue, 13 Dec 2011 15:10:02 +0000 Cc: Mauro Carvalho Chehab , Sumit Semwal , "linux@arm.linux.org.uk" , "jesse.barker@linaro.org" , "linux-kernel@vger.kernel.org" , "dri-devel@lists.freedesktop.org" , "linaro-mm-sig@lists.linaro.org" , "linux-mm@kvack.org" , "daniel@ffwll.ch" , "linux-arm-kernel@lists.infradead.org" , "linux-media@vger.kernel.org" References: <1322816252-19955-1-git-send-email-sumit.semwal@ti.com> <4EE33EC2.6050508@redhat.com> <20111212224408.GD4355@morell.nvidia.com> In-Reply-To: <20111212224408.GD4355@morell.nvidia.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201112131510.02785.arnd@arndb.de> Sender: linux-media-owner@vger.kernel.org List-ID: On Monday 12 December 2011, Robert Morell wrote: > > > > Doing a buffer sharing with something that is not GPL is not fun, as, if any > > issue rises there, it would be impossible to discover if the problem is either > > at the closed-source driver or at the open source one. At the time I was using > > the Nvidia proprietary driver, it was very common to have unexplained issues > > caused likely by bad code there at the buffer management code, causing X > > applications and extensions (like xv) to break. > > > > We should really make this EXPORT_SYMBOL_GPL(), in order to be able to latter > > debug future share buffer issues, when needed. > > Sorry, I don't buy this argument. Making these exports GPL-only is not > likely to cause anybody to open-source their driver, but will rather > just cause them to use yet more closed-source code that is even less > debuggable than this would be, to those without access to the source. But at least the broken module then won't be interacting with other modules because it cannot share any buffers. Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx153.postini.com [74.125.245.153]) by kanga.kvack.org (Postfix) with SMTP id 632F46B026A for ; Tue, 13 Dec 2011 10:10:15 -0500 (EST) From: Arnd Bergmann Subject: Re: [Linaro-mm-sig] [RFC v2 1/2] dma-buf: Introduce dma buffer sharing mechanism Date: Tue, 13 Dec 2011 15:10:02 +0000 References: <1322816252-19955-1-git-send-email-sumit.semwal@ti.com> <4EE33EC2.6050508@redhat.com> <20111212224408.GD4355@morell.nvidia.com> In-Reply-To: <20111212224408.GD4355@morell.nvidia.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201112131510.02785.arnd@arndb.de> Sender: owner-linux-mm@kvack.org List-ID: To: Robert Morell Cc: Mauro Carvalho Chehab , Sumit Semwal , "linux@arm.linux.org.uk" , "jesse.barker@linaro.org" , "linux-kernel@vger.kernel.org" , "dri-devel@lists.freedesktop.org" , "linaro-mm-sig@lists.linaro.org" , "linux-mm@kvack.org" , "daniel@ffwll.ch" , "linux-arm-kernel@lists.infradead.org" , "linux-media@vger.kernel.org" On Monday 12 December 2011, Robert Morell wrote: > > > > Doing a buffer sharing with something that is not GPL is not fun, as, if any > > issue rises there, it would be impossible to discover if the problem is either > > at the closed-source driver or at the open source one. At the time I was using > > the Nvidia proprietary driver, it was very common to have unexplained issues > > caused likely by bad code there at the buffer management code, causing X > > applications and extensions (like xv) to break. > > > > We should really make this EXPORT_SYMBOL_GPL(), in order to be able to latter > > debug future share buffer issues, when needed. > > Sorry, I don't buy this argument. Making these exports GPL-only is not > likely to cause anybody to open-source their driver, but will rather > just cause them to use yet more closed-source code that is even less > debuggable than this would be, to those without access to the source. But at least the broken module then won't be interacting with other modules because it cannot share any buffers. Arnd -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Tue, 13 Dec 2011 15:10:02 +0000 Subject: [Linaro-mm-sig] [RFC v2 1/2] dma-buf: Introduce dma buffer sharing mechanism In-Reply-To: <20111212224408.GD4355@morell.nvidia.com> References: <1322816252-19955-1-git-send-email-sumit.semwal@ti.com> <4EE33EC2.6050508@redhat.com> <20111212224408.GD4355@morell.nvidia.com> Message-ID: <201112131510.02785.arnd@arndb.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Monday 12 December 2011, Robert Morell wrote: > > > > Doing a buffer sharing with something that is not GPL is not fun, as, if any > > issue rises there, it would be impossible to discover if the problem is either > > at the closed-source driver or at the open source one. At the time I was using > > the Nvidia proprietary driver, it was very common to have unexplained issues > > caused likely by bad code there at the buffer management code, causing X > > applications and extensions (like xv) to break. > > > > We should really make this EXPORT_SYMBOL_GPL(), in order to be able to latter > > debug future share buffer issues, when needed. > > Sorry, I don't buy this argument. Making these exports GPL-only is not > likely to cause anybody to open-source their driver, but will rather > just cause them to use yet more closed-source code that is even less > debuggable than this would be, to those without access to the source. But at least the broken module then won't be interacting with other modules because it cannot share any buffers. Arnd