From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751821AbaLVWlF (ORCPT ); Mon, 22 Dec 2014 17:41:05 -0500 Received: from devils.ext.ti.com ([198.47.26.153]:33810 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751110AbaLVWlD (ORCPT ); Mon, 22 Dec 2014 17:41:03 -0500 Message-ID: <54989DDE.3060409@ti.com> Date: Mon, 22 Dec 2014 17:40:30 -0500 From: Murali Karicheri User-Agent: Mozilla/5.0 (X11; Linux i686; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: Arnd Bergmann CC: , , , , , , , Subject: Re: [RFC v1 PATCH 1/2] of/pci: add of_pci_dma_configure() update dma configuration References: <1418940425-2017-1-git-send-email-m-karicheri2@ti.com> <11285984.OK9CqQGmjZ@wuerfel> <54988FDB.8000108@ti.com> <2285493.QXo0OxClZ5@wuerfel> In-Reply-To: <2285493.QXo0OxClZ5@wuerfel> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/22/2014 05:24 PM, Arnd Bergmann wrote: > On Monday 22 December 2014 16:40:43 Murali Karicheri wrote: >>>> +++ b/arch/arm/mm/dma-mapping.c >>>> @@ -2052,9 +2052,10 @@ void arch_setup_dma_ops(struct device *dev, u64 >>>> dma_base, u64 size, >>>> struct iommu_ops *iommu, bool coherent) >>>> { >>>> struct dma_map_ops *dma_ops; >>>> + u64 temp_size = min((*(dev->dma_mask) + 1), size); >>>> >>>> dev->archdata.dma_coherent = coherent; >>>> - if (arm_setup_iommu_dma_ops(dev, dma_base, size, iommu)) >>>> + if (arm_setup_iommu_dma_ops(dev, dma_base, temp_size, iommu)) >>>> >>>> If you agree, I will post v1 of the patch with these updates. Let me >>>> know. I did some basic tests on Keystone with these changes and it works >>>> fine. >>> >>> It's not exactly what I meant. My main point was that we need to limit >>> dev->dma_mask to (size-1) here, but you are not touching that. >> >> if you mean overriding the dev->dma_mask to min((*dev->dma_mask), >> size-1), then I am getting the error "Coherent DMA mask 0x7fffffff (pfn >> 0x780000-0x800000) covers a smaller range of system memory than the DMA >> zone pfn 0x0-0x880000) when the devices on Keystone tries to set the dma >> mask. Something wrong and I need to look into the code. > > Right, it sounds like the offset was applied incorrectly at some point. > > What are the DMA zone size and the phys-offset? 2G and 0x8_0000_0000. This limit the usable DMA size to 2G on Keystone, I believe you shouldn't be limiting the dma mask to size-1 in this case, right? The DT setup the dma-range to have a size of 2G (0x80000000). Murali > > Arnd -- Murali Karicheri Linux Kernel, Texas Instruments