From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id BA7F9DDEE4 for ; Mon, 21 Jul 2008 05:48:42 +1000 (EST) Date: Sun, 20 Jul 2008 12:48:41 -0700 From: Arjan van de Ven To: Stefan Richter Subject: Re: dma_alloc_coherent() on PPC32: physical addresses above 2G possible? Message-ID: <20080720124841.0e5e8de0@infradead.org> In-Reply-To: <4883913F.9040706@s5r6.in-berlin.de> References: <488385A7.4010509@s5r6.in-berlin.de> <20080720114358.6c88e048@infradead.org> <4883913F.9040706@s5r6.in-berlin.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Cc: linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Sun, 20 Jul 2008 21:25:51 +0200 Stefan Richter wrote: > Arjan van de Ven wrote: > > On Sun, 20 Jul 2008 20:36:23 +0200 > > Stefan Richter wrote: > > > >> PS: I don't want to set the DMA mask of this device to > >> DMA_31BIT_MASK because that would be detrimental to other functions > >> of the device. It's a TI TSB43AB22A FireWire controller. > > > > Hi, > > > > just want to mention that you can set the coherent mask separately > > from the generic mask... is that sufficient for your load? > > (you can even set it just for this allocation..) > > Hmm. Would that be done this way? > During probe: > > if (chip_is_tsb43ab22a) { > if (dma_supported(dev, DMA_31BIT_MASK)) > chip->needs_dma_mask_workaround = 1; > else > chip->needs_some_other_workaround = 1; > } btw it might be nicer to make this chip->something_special_mask = DMA_31BIT_MASK; then you can just use the mask from this struct rather than another check -- If you want to reach me at my work email, use arjan@linux.intel.com For development, discussion and tips for power savings, visit http://www.lesswatts.org