From: David Miller <davem@davemloft.net>
To: timur@codeaurora.org
Cc: David.Laight@ACULAB.COM, netdev@vger.kernel.org
Subject: Re: [PATCH 3/4] net: qcom/emac: enforce DMA address restrictions
Date: Thu, 12 Oct 2017 09:58:37 -0700 (PDT) [thread overview]
Message-ID: <20171012.095837.2057549694773237248.davem@davemloft.net> (raw)
In-Reply-To: <e523734d-d845-8eae-4a5b-e679b8e46654@codeaurora.org>
From: Timur Tabi <timur@codeaurora.org>
Date: Thu, 12 Oct 2017 09:13:25 -0500
> On 10/12/17 4:30 AM, David Laight wrote:
>> Isn't the memory allocated by a single kzalloc() call?
>
> dma_alloc_coherenent, actually.
>
>> IIRC that guarantees it doesn't cross a power or 2 boundary less than
>> the size.
>
> I'm pretty sure that kzalloc does not make that guarantee, and I don't
> think dma_alloc_coherent does either.
Both make that guarantee, even when an IOMMU is used.
next prev parent reply other threads:[~2017-10-12 16:58 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-11 19:52 [PATCH 0/4] net: qcom/emac: various minor fixes Timur Tabi
2017-10-11 19:52 ` [PATCH 1/4] net: qcom/emac: specify the correct DMA mask Timur Tabi
2017-10-11 19:52 ` [PATCH 2/4] net: qcom/emac: remove unused address arrays Timur Tabi
2017-10-11 19:52 ` [PATCH 3/4] net: qcom/emac: enforce DMA address restrictions Timur Tabi
2017-10-12 9:30 ` David Laight
2017-10-12 14:13 ` Timur Tabi
2017-10-12 16:20 ` David Laight
2017-10-12 16:52 ` Timur Tabi
2017-10-12 16:58 ` David Miller [this message]
2017-10-12 17:15 ` Timur Tabi
2017-10-12 17:20 ` David Miller
2017-10-11 19:52 ` [PATCH 4/4] net: qcom/emac: clean up some TX/RX error messages Timur Tabi
2017-10-11 23:02 ` [PATCH 0/4] net: qcom/emac: various minor fixes David Miller
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