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Date:   Fri, 13 May 2022 02:28:11 +0300
From:   Serge Semin <fancer.lancer@gmail.com>
To:     Christoph Hellwig <hch@lst.de>
Cc:     Serge Semin <Sergey.Semin@baikalelectronics.ru>,
        Gustavo Pimentel <gustavo.pimentel@synopsys.com>,
        Vinod Koul <vkoul@kernel.org>,
        Jingoo Han <jingoohan1@gmail.com>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Frank Li <Frank.Li@nxp.com>,
        Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        Robin Murphy <robin.murphy@arm.com>,
        Vladimir Murzin <vladimir.murzin@arm.com>,
        Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>,
        Pavel Parkhomenko <Pavel.Parkhomenko@baikalelectronics.ru>,
        Rob Herring <robh@kernel.org>,
        Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= <kw@linux.com>,
        linux-pci@vger.kernel.org, dmaengine@vger.kernel.org,
        linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org
Subject: Re: [PATCH v2 01/26] dma-direct: take dma-ranges/offsets into
 account in resource mapping
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References: <20220503225104.12108-1-Sergey.Semin@baikalelectronics.ru>
 <20220503225104.12108-2-Sergey.Semin@baikalelectronics.ru>
 <20220509061552.GA17190@lst.de>
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On Mon, May 09, 2022 at 08:15:52AM +0200, Christoph Hellwig wrote:
> So I think the big problem pointed out by Robin is that existing DTs
> might not take this into account. 

I'd say that the biggest problem isn't in the DT part but in the
drivers using the dma_map_resource() method since they don't expect
the non-uniform DMA-direct mapping can be available.

> So I think we need to do a little
> research and at least Cc all maintainers and lists for relevant in-tree
> DTs for drivers that use dma_map_resource to discuss this.

Right. I'll send the next patchset revision out with all possibly
interested maintainers and lists in Cc of this patch.

-Sergey

>