From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King Subject: Re: buffer producer/consumer sync Date: Wed, 31 Mar 2004 09:53:06 +0100 Sender: alsa-devel-admin@lists.sourceforge.net Message-ID: <20040331095306.A32258@flint.arm.linux.org.uk> References: <20040331083114.C27804@flint.arm.linux.org.uk> <20040331085330.A30701@flint.arm.linux.org.uk> <20040331091124.B30701@flint.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: ; from perex@suse.cz on Wed, Mar 31, 2004 at 10:29:06AM +0200 Errors-To: alsa-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Jaroslav Kysela Cc: "Gupta, Kshitij" , alsa-devel@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org On Wed, Mar 31, 2004 at 10:29:06AM +0200, Jaroslav Kysela wrote: > On Wed, 31 Mar 2004, Russell King wrote: > > Keeping the existing ->nopage will not work - there is no way to get to > > a struct page on ARM given the information available to the ALSA code. > > Looking to arch/arm/mm/consistent.c - vm_region_find / pfn_to_page? No - we don't have a pfn to start with, and I'm not implementing an interface which returns a struct page because, as was agreed on linux-arch, such an interface is completely wrong. The correct interface is dma_mmap_coherent(). I'm actually tempted to provide dma_mmap_coherent() and just let everyone else whinge and moan that the API doesn't meet their expectations. BTW, ARM also needs the mark_pages and unmark_pages functions commented out since they're also trying to use virt_to_page() on virtual addresses that this function is not supposed to - except for the ISA DMA case (and yes, we have ISA DMA-based sound cards as well.) -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 PCMCIA - http://pcmcia.arm.linux.org.uk/ 2.6 Serial core ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click