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Date:   Tue, 22 Feb 2022 16:59:04 +0100
From:   Christoph Hellwig <hch@lst.de>
To:     Baoquan He <bhe@redhat.com>
Cc:     Christoph Hellwig <hch@lst.de>, linux-kernel@vger.kernel.org,
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Subject: Re: [PATCH 1/2] dma-mapping: check dma_mask for streaming mapping
 allocs
Message-ID: <20220222155904.GA13323@lst.de>
References: <20220219005221.634-1-bhe@redhat.com> <20220219005221.634-22-bhe@redhat.com> <20220219071730.GG26711@lst.de> <20220220084044.GC93179@MiWiFi-R3L-srv> <20220222084530.GA6210@lst.de> <YhSpaGfiQV8Nmxr+@MiWiFi-R3L-srv> <20220222131120.GB10093@lst.de> <YhToFzlSufrliUsi@MiWiFi-R3L-srv>
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On Tue, Feb 22, 2022 at 09:41:43PM +0800, Baoquan He wrote:
> For newly added streaming mapping APIs, the internal core function
> __dma_alloc_pages() should check dev->dma_mask, but not
> ev->coherent_dma_mask which is for coherent mapping.

No, this is wrong.  dev->coherent_dma_mask is and should be used here.

>
> 
> Meanwhile, just filter out gfp flags if they are any of
> __GFP_DMA, __GFP_DMA32 and __GFP_HIGHMEM, but not fail it. This change
> makes it  consistent with coherent mapping allocs.

This is wrong as well.  We want to eventually fail dma_alloc_coherent
for these, too.  It just needs more work.