[PATCH v5 0/2] ethtool: implement Energy Detect Powerdown support via phy-tunable

From: Alexandru Ardelean
Date: Mon Sep 16 2019 - 03:36:06 EST


This changeset proposes a new control for PHY tunable to control Energy
Detect Power Down.

The `phy_tunable_id` has been named `ETHTOOL_PHY_EDPD` since it looks like
this feature is common across other PHYs (like EEE), and defining
`ETHTOOL_PHY_ENERGY_DETECT_POWER_DOWN` seems too long.

The way EDPD works, is that the RX block is put to a lower power mode,
except for link-pulse detection circuits. The TX block is also put to low
power mode, but the PHY wakes-up periodically to send link pulses, to avoid
lock-ups in case the other side is also in EDPD mode.

Currently, there are 2 PHY drivers that look like they could use this new
PHY tunable feature: the `adin` && `micrel` PHYs.

This series updates only the `adin` PHY driver to support this new feature,
as this chip has been tested. A change for `micrel` can be proposed after a
discussion of the PHY-tunable API is resolved.

Alexandru Ardelean (2):
ethtool: implement Energy Detect Powerdown support via phy-tunable
net: phy: adin: implement Energy Detect Powerdown mode via phy-tunable

drivers/net/phy/adin.c | 61 ++++++++++++++++++++++++++++++++++++
include/uapi/linux/ethtool.h | 22 +++++++++++++
net/core/ethtool.c | 6 ++++
3 files changed, 89 insertions(+)

--

Changelog v4 -> v5:
* add Andrew's & Florian's Reviewed-by tags for patch 1
* fixed patch 2 goof:
`rc = adin_set_edpd(phydev, 1);`
->
`rc = adin_set_edpd(phydev, ETHTOOL_PHY_EDPD_DFLT_TX_MSECS);`
this was omitted when re-spin to v4 was done
* for patch 2 added Florian's Reviewed-by tag as this was suggested by him
and his accord was
`with that fixed: Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx>`

Changelog v3 -> v4:
* impose the TX interval unit for EDPD to be milliseconds; the point was
raised by Michal; this should allow for intervals:
- as small as 1 millisecond, which does not sound like a power-saver
- as large as 65 seconds, which sounds like a lot to wait for a link to
come up

Changelog v2 -> v3:
* implement Andrew's review comments:
1. for patch `ethtool: implement Energy Detect Powerdown support via
phy-tunable`
- ETHTOOL_PHY_EDPD_DFLT_TX_INTERVAL == 0xffff
- ETHTOOL_PHY_EDPD_NO_TX == 0xfffe
- added comment in include/uapi/linux/ethtool.h
2. for patch `net: phy: adin: implement Energy Detect Powerdown mode via
phy-tunable`
- added comments about interval & units for the ADIN PHY
- in `adin_set_edpd()`: add a switch statement of all the valid values
- in `adin_get_edpd()`: return `ETHTOOL_PHY_EDPD_DFLT_TX_INTERVAL`
since the PHY only supports a single TX-interval value (1 second)

Changelog v1 -> v2:
* initial series was made up of 2 sub-series: 1 for kernel & 1 for ethtool
in userspace; v2 contains only the kernel series

2.20.1