Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756132AbbBFU1q (ORCPT ); Fri, 6 Feb 2015 15:27:46 -0500 Received: from comal.ext.ti.com ([198.47.26.152]:55148 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751193AbbBFU1o (ORCPT ); Fri, 6 Feb 2015 15:27:44 -0500 Message-ID: <54D5238F.4030608@ti.com> Date: Fri, 6 Feb 2015 15:26:55 -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: Catalin Marinas CC: "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "iommu@lists.linux-foundation.org" , "devicetree@vger.kernel.org" , "linux-pci@vger.kernel.org" , Russell King , Arnd Bergmann , Joerg Roedel , Will Deacon , Rob Herring , Bjorn Helgaas , "suravee.suthikulpanit@amd.com" , "grant.likely@linaro.org" Subject: Re: [PATCH v6 3/7] of: fix size when dma-range is not used References: <1423173179-10227-1-git-send-email-m-karicheri2@ti.com> <1423173179-10227-4-git-send-email-m-karicheri2@ti.com> <20150206143812.GB20549@localhost> <54D4D59F.6050408@ti.com> <20150206151210.GC23190@e104818-lin.cambridge.arm.com> In-Reply-To: <20150206151210.GC23190@e104818-lin.cambridge.arm.com> 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 Content-Length: 3380 Lines: 90 On 02/06/2015 10:12 AM, Catalin Marinas wrote: > On Fri, Feb 06, 2015 at 02:54:23PM +0000, Murali Karicheri wrote: >> On 02/06/2015 09:38 AM, Catalin Marinas wrote: >>> On Thu, Feb 05, 2015 at 09:52:55PM +0000, Murali Karicheri wrote: >>>> Fix the dma-range size when the DT attribute is missing. i.e set size to >>>> dev->coherent_dma_mask + 1 instead of dev->coherent_dma_mask. Also add >>>> code to check invalid values of size configured in DT and log error. >>>> >>>> Cc: Joerg Roedel >>>> Cc: Grant Likely >>>> Cc: Rob Herring >>>> Cc: Bjorn Helgaas >>>> Cc: Will Deacon >>>> Cc: Russell King >>>> Cc: Arnd Bergmann >>>> Cc: Suravee Suthikulpanit >>>> >>>> Signed-off-by: Murali Karicheri >>>> --- >>>> drivers/of/device.c | 17 ++++++++++++++++- >>>> 1 file changed, 16 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/drivers/of/device.c b/drivers/of/device.c >>>> index 2de320d..314c8a9 100644 >>>> --- a/drivers/of/device.c >>>> +++ b/drivers/of/device.c >>>> @@ -105,9 +105,24 @@ void of_dma_configure(struct device *dev, struct device_node *np) >>>> ret = of_dma_get_range(np,&dma_addr,&paddr,&size); >>>> if (ret< 0) { >>>> dma_addr = offset = 0; >>>> - size = dev->coherent_dma_mask; >>>> + size = dev->coherent_dma_mask + 1; >>>> } else { >>>> offset = PFN_DOWN(paddr - dma_addr); >>>> + >>>> + /* >>>> + * Add a work around to treat the size as mask + 1 in case >>>> + * it is defined in DT as a mask. >>>> + */ >>>> + if (size& 1) { >>>> + dev_warn(dev, "Invalid size 0x%llx for dma-range\n", >>>> + size); >>>> + size = size + 1; >>>> + } >>>> + >>>> + if (!size) { >>>> + dev_err(dev, "Adjusted size 0x%llx invalid\n", size); >>>> + return; >>>> + } >>> >>> Would it make sense to set coherent_dma_mask to 0 here to make this more >>> noticeable? It can be done together with the mask calculation from size. >> >> I guess you are the following in the code. >> >> if (!size) { >> dev->coherent_dma_mask = 0; >> dev_err(dev, "Adjusted size 0x%llx invalid\n", size); >> return; >> } >> >> Not sure how this is going to help and how this get handled by the >> caller and subsequent logic. Probably it will cause probe to fail, with >> some helpful error code. > > Not sure how it will fail, maybe the driver figures out that DMA isn't > available and say something or switch to PIO. I guess you can leave it > as 32-bit mask by default for now even in case of size == 0. > > BTW, since pci_device_add() already sets coherent_dma_mask, you could > add another check at the beginning of of_dma_configure(): > > if (!dev->coherent_dma_mask) > dev->coherent_dma_mask = DMA_BIT_MASK(32); > > That's more of a nitpick as the values are both the same. > Catalin, Just posted a patch for size based dma mask with title "of: calculate masks of the device based on dma-range size". Please review and comment -- Murali Karicheri Linux Kernel, Texas Instruments -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/