From mboxrd@z Thu Jan 1 00:00:00 1970 From: "White, Charles" Date: Mon, 09 Jul 2001 15:33:24 +0000 Subject: RE: [Linux-ia64] RE: DMA memory limitation? Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org Yes, I thought about doing it that way, and it COULD be done, but right now the driver allocates command buffer for IOCTLs as needed. So the pci_dev set to NULL allows to continue to do that... -----Original Message----- From: Matt_Domsch@Dell.com [mailto:Matt_Domsch@Dell.com] Sent: Monday, July 09, 2001 10:20 AM To: White, Charles Cc: linux-ia64@linuxia64.org Subject: RE: [Linux-ia64] RE: DMA memory limitation? > My device has the limitation that the command buffers I send > must be in 32 > bit space, but the IO can be in 64 bit. But there is only > ONE dma_mask for the device. Ahh, yes. The AMI MegaRAID driver/controllers have the same requirements. megaraid solved it as: pci_find_device() finds their device, they get a pci_dev back which has a 32-bit dma_mask. pci_alloc_consistent() the mailbox (this must be in 32-bit space). if it's a 64-bit-capable controller, set pci_dev->dma_mask ~0L. pci_alloc_consistent() the command buffers and scatter-gather lists (these can be in 64-bit space). Could something similar work for you? Thanks, Matt -- Matt Domsch Sr. Software Engineer Dell Linux Solutions www.dell.com/linux #2 Linux Server provider with 17% in the US and 14% Worldwide (IDC)! #3 Unix provider with 18% in the US (Dataquest)!