RE: [PATCH v2] uio: dfl: add HSSI feature id

From: matthew . gerlach
Date: Tue Apr 26 2022 - 13:54:24 EST

On Tue, 26 Apr 2022, Wu, Hao wrote:

-----Original Message-----
From: Zhang, Tianfei <tianfei.zhang@xxxxxxxxx>
Sent: Tuesday, April 12, 2022 2:24 PM
To: Wu, Hao <hao.wu@xxxxxxxxx>; trix@xxxxxxxxxx; mdf@xxxxxxxxxx; Xu,
Yilun <yilun.xu@xxxxxxxxx>; linux-fpga@xxxxxxxxxxxxxxx;
Cc: linux-kernel@xxxxxxxxxxxxxxx; Matthew Gerlach
<matthew.gerlach@xxxxxxxxxxxxxxx>; Zhang, Tianfei
Subject: [PATCH v2] uio: dfl: add HSSI feature id

From: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>

Add the feature id of the OFS HSSI (High Speed Serial Interface)

We still don't see any description on what OFS is here, or will OFS be added to
title as well? we don't expect another submission with the same title but for
HSSI again.

This name of HSSI module in dfl feature id table is : OFS HSSI subsystem.

How about this tile:
uio: dfl: add OFS HSSI device id

Add OFS HSSI (Open FPGA Stack High Speed Serial Interface) device ID in
uio_dfl driver for Intel PAC N6000 Card.

Hi Tianfei,

In the Platform Designer tool, this IP block is referred to as the HSSI
Subsystem. I think we should use the same name here. Additionally, this
subsystem is already in use in multiple cards; so I suggest dropping
any reference to a particular card.

The only concern is that there are 4 HSSI in the feature id table.
Without any prefix, it may confuse people.

Hi Hao,

Good point about the possible confusion of 4 HSSI implementations mentioned in the table. I have submitted a pull request adding clarity to the table:



subsystem to table of ids supported by the uio_dfl driver. HSSI
subsystem consists of harden/soft Ethernet MAC to support various
ethernet usages and PCS/FEC/PMA direct modes for non-ethernet usages.

We leverage the uio_dfl driver to access the HSSI subsystem on user
space, because the HSSI subsystem was designed for specific purposes
and does not fit into the standard MAC and net kernel subsystems.

The Feature ID table of DFL can be found:

Why you put it here? even this link there is no more descriptions to
what it is. Or can be removed here.

Yes, I agree, I will remove it.

Signed-off-by: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>
Signed-off-by: Tianfei Zhang <tianfei.zhang@xxxxxxxxx>
v2: add HSSI introduction and the git repo of Feature ID table.
drivers/uio/uio_dfl.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/uio/uio_dfl.c b/drivers/uio/uio_dfl.c index
89c0fc7b0cbc..660e1d0bf6b9 100644
--- a/drivers/uio/uio_dfl.c
+++ b/drivers/uio/uio_dfl.c
@@ -45,9 +45,11 @@ static int uio_dfl_probe(struct dfl_device *ddev)


static const struct dfl_device_id uio_dfl_ids[] = {
{ }
MODULE_DEVICE_TABLE(dfl, uio_dfl_ids);