netdev - Re: [PATCH V7 7/9] PCI/sysfs: Add a 10-Bit Tag sysfs file

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Message-ID: <20210804235211.GA1693993@bjorn-Precision-5520>
Date:   Wed, 4 Aug 2021 18:52:11 -0500
From:   Bjorn Helgaas <helgaas@...nel.org>
To:     Dongdong Liu <liudongdong3@...wei.com>
Cc:     hch@...radead.org, kw@...ux.com, logang@...tatee.com,
        leon@...nel.org, linux-pci@...r.kernel.org, rajur@...lsio.com,
        hverkuil-cisco@...all.nl, linux-media@...r.kernel.org,
        netdev@...r.kernel.org
Subject: Re: [PATCH V7 7/9] PCI/sysfs: Add a 10-Bit Tag sysfs file

On Wed, Aug 04, 2021 at 09:47:06PM +0800, Dongdong Liu wrote:
> PCIe spec 5.0 r1.0 section 2.2.6.2 says that if an Endpoint supports
> sending Requests to other Endpoints (as opposed to host memory), the
> Endpoint must not send 10-Bit Tag Requests to another given Endpoint
> unless an implementation-specific mechanism determines that the Endpoint
> supports 10-Bit Tag Completer capability. Add a 10bit_tag sysfs file,
> write 0 to disable 10-Bit Tag Requester when the driver does not bind
> the device if the peer device does not support the 10-Bit Tag Completer.
> This will make P2P traffic safe. the 10bit_tag file content indicate
> current 10-Bit Tag Requester Enable status.
> 
> Signed-off-by: Dongdong Liu <liudongdong3@...wei.com>

> +		The file is also writeable, the value only accept by write 0
> +		to disable 10-Bit Tag Requester when the driver does not bind
> +		the deivce. The typical use case is for p2pdma when the peer
> +		device does not support 10-BIT Tag Completer.

s/10-BIT/10-Bit/