From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ralf Baechle Subject: Re: [PATCH 3/5] ALSA: pcm - fix page conversion on non-coherent MIPS arch Date: Fri, 27 Nov 2009 08:46:35 +0000 Message-ID: <20091127084635.GA18741@linux-mips.org> References: <1259248388-20095-1-git-send-email-tiwai@suse.de> <1259248388-20095-2-git-send-email-tiwai@suse.de> <1259248388-20095-3-git-send-email-tiwai@suse.de> <1259248388-20095-4-git-send-email-tiwai@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from h5.dl5rb.org.uk (h5.dl5rb.org.uk [81.2.74.5]) by alsa0.perex.cz (Postfix) with ESMTP id 33FDF1038A0 for ; Fri, 27 Nov 2009 09:46:22 +0100 (CET) Content-Disposition: inline In-Reply-To: <1259248388-20095-4-git-send-email-tiwai@suse.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: Takashi Iwai Cc: linux-mips@linux-mips.org, alsa-devel@alsa-project.org, Thomas Bogendoerfer , Becky Bruce , Wu Zhangjin , Benjamin Herrenschmidt , Kumar Gala List-Id: alsa-devel@alsa-project.org On Thu, Nov 26, 2009 at 04:13:06PM +0100, Takashi Iwai wrote: > The non-coherent MIPS arch doesn't give the correct address by a simple > virt_to_page() for pages allocated via dma_alloc_coherent(). > > Original patch by Wu Zhangjin . A proper check of the > buffer allocation type was added to avoid the wrong conversion. The origins of this patch go back far further. The oldest patch I could find which is a superset of this was written by Atsushi Nemoto and various incarnations of it have been sumitted to and reject by me a number of times through the years. > Note that this doesn't fix perfectly: the pages should be marked with > proper pgprot value. This will be done in a future implementation like > the conversion to dma_mmap_coherent(). > > Signed-off-by: Takashi Iwai So while this is ugly I don't think this patch will actually make the the situation worse for any MIPS platform. So with both eyes closed: Acked-by: Ralf Baechle Ralf