From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 6 Dec 2002 11:30:07 -0700 From: Matt Porter To: Joakim Tjernlund Cc: Matt Porter , Pantelis Antoniou , linuxppc-embedded@lists.linuxppc.org Subject: Re: Regarding consistent_alloc Message-ID: <20021206113007.B18257@home.com> References: <20021206085909.B17918@home.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: ; from joakim.tjernlund@lumentis.se on Fri, Dec 06, 2002 at 05:08:22PM +0100 Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: On Fri, Dec 06, 2002 at 05:08:22PM +0100, Joakim Tjernlund wrote: > > > > On Fri, Dec 06, 2002 at 03:25:48PM +0100, Joakim Tjernlund wrote: > > > If you implement the performance improvement I suggested earlier, I don't think > > > you need them. Another thing with consistent_xxx() is that you can not use > > > __pa() and __va() on addresses returned by the consistent_alloc et. al. > > > > Um, well if you are doing a consistent_alloc() then surely you are > > keeping the dma_handle around which is your physical address. If you > > want the kernel virtual address then you can apply __va to that. So, > > you have the cache inhibited mapping in vmalloc space returned to you, > > the physical address provided in dma_handle, and a kernel virtual address > > that can be trivially generated. > > m8xx_cpm_hostalloc() does not keep the DMA handle and __pa() does not work > on addresses returned by m8xx_cpm_hostalloc(). I just found that out the > hard way when upgrading from MV 2.4.2 to linuxppc_2_4_devel 2.4.20. My SPI driver that's a problem with m8xx_cpm_hostalloc() (or how you are using it) if it doesn't keep around the values you need. -- Matt Porter porter@cox.net This is Linux Country. On a quiet night, you can hear Windows reboot. ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/