From: Jon Masters <jcm@jonmasters.org>
To: Valmiki <valmikibow@gmail.com>,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: lorenzo.pieralisi@arm.com, bhelgaas@google.com, robh@kernel.org
Subject: Re: dma-coherent property for PCIe Root
Date: Thu, 1 Oct 2020 01:16:10 -0400 [thread overview]
Message-ID: <269995f2-d57b-d218-8730-fe729cc9dec2@jonmasters.org> (raw)
In-Reply-To: <1512d7b5-54c6-3b87-0090-5e370955223e@gmail.com>
On 9/14/20 1:23 AM, Valmiki wrote:
> Hi All,
>
> How does "dma-coherent" property will work for PCIe as RC on an
> ARM SOC ?
> Because the end point device drivers are the one which will request dma
> buffers and Root port driver doesn't involve in data path of end point
> except for handling interrupts.
>
> How does EP DMA buffers will be hardware coherent if RC driver exposes
> dma-coherent property ?
This simply means that the RC supports maintaining coherency, it doesn't
mean that the RC driver does anything. It's a property of the hardware.
Jon.
--
Computer Architect
prev parent reply other threads:[~2020-10-01 5:16 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-14 5:23 dma-coherent property for PCIe Root Valmiki
2020-10-01 5:16 ` Jon Masters [this message]
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