After the discussion here:
https://lore.kernel.org/netdev/20210603143453.if7hgifupx5k433b@pali/
which resulted in this patch:
https://patchwork.kernel.org/project/netdevbpf/patch/20210704134325.24842-1-pali@kernel.org/
and many other discussions before it, notably:
https://patchwork.kernel.org/project/linux-arm-kernel/patch/1512016235-15909-1-git-send-email-Bhaskar.Upadhaya@nxp.com/
it became apparent that nobody really knows what "SGMII 2500" is.
Certainly, Freescale/NXP hardware engineers name this protocol
"SGMII 2500" in the reference manuals, but the PCS devices do not
support any "SGMII" specific features when operating at the speed of
2500 Mbps, no in-band autoneg and no speed change via symbol replication
. So that leaves a fixed speed of 2500 Mbps using a coding of 8b/10b
with a SERDES lane frequency of 3.125 GHz. In fact, "SGMII 2500 without
in-band autoneg and at a fixed speed" is indistinguishable from
"2500base-x without in-band autoneg", which is precisely what these NXP
devices support.
So it just appears that "SGMII 2500" is an unclear name with no clear
definition that stuck.
As such, in the Linux kernel, the drivers which use this SERDES protocol
use the 2500base-x phy-mode.
This patch converts U-Boot to use 2500base-x too, or at least, as much
as it can.
Note that I would have really liked to delete PHY_INTERFACE_MODE_SGMII_2500
completely, but the mvpp2 driver seems to even distinguish between SGMII
2500 and 2500base-X. Namely, it enables in-band autoneg for one but not
the other, and forces flow control for one but not the other. This goes
back to the idea that maybe 2500base-X is a fiber protocol and SGMII-2500
is an MII protocol (connects a MAC to a PHY such as Aquantia), but the
two are practically indistinguishable through everything except use case.
NXP devices can support both use cases through an identical configuration,
for example RX flow control can be unconditionally enabled in order to
support rate adaptation performed by an Aquantia PHY. At least I can
find no indication in online documents published by Cisco which would
point towards "SGMII-2500" being an actual standard with an actual
definition, so I cannot say "yes, NXP devices support it".
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
The correct setting for the RGMII ports on LS1043ARDB is to
enable delay on both Rx and Tx so the interface mode used must
be PHY_INTERFACE_MODE_RGMII_ID. There is a pull-up that turns
on Rx internal delay by default and the u-boot does not
override that (yet) so in u-boot the interface is functional.
In Linux the PHY driver is clearing the Rx delay for the
"rgmii-txid" mode and the reception does not work.
Changing the RGMII mode to internal delay here ensures that
device tree fix-ups for the PHY connection type turn on both
Tx and Rx internal delay in Linux.
Fixes: 5a78a472f6 ("armv8/ls1043a: RGMII PHY requires internal
delay on Tx")
Signed-off-by: Madalin Bucur <madalin.bucur@oss.nxp.com>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from. So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry. Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.
In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.
This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents. There's also a few places where I found we did not have a tag
and have introduced one.
Signed-off-by: Tom Rini <trini@konsulko.com>
Remove verbose message for FMan port.
Signed-off-by: Mingkai Hu <Mingkai.Hu@freescale.com>
[York Sun: Added commit message]
Reviewed-by: York Sun <yorksun@freescale.com>
Signed-off-by: Hou Zhiqiang <B48286@freescale.com>
Signed-off-by: Shaohui Xie <Shaohui.Xie@freescale.com>
Signed-off-by: Mingkai Hu <Mingkai.Hu@freescale.com>
Signed-off-by: Gong Qianyu <Qianyu.Gong@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>
