Re: [PATCH 14/15] net: phy: add PHY regulator support

wt., 23 cze 2020 o 11:43 Russell King - ARM Linux admin
[off-list ref] napisał(a):

On Tue, Jun 23, 2020 at 11:41:11AM +0200, Bartosz Golaszewski wrote:

quoted

pon., 22 cze 2020 o 15:29 Russell King - ARM Linux admin
[off-list ref] napisał(a):

quoted

[snip!]

quoted

This is likely to cause issues for some PHY drivers.  Note that we have
some PHY drivers which register a temperature sensor in the probe
function, which means they can be accessed independently of the lifetime
of the PHY bound to the network driver (which may only be while the
network device is "up".)  We certainly do not want hwmon failing just
because the network device is down.

That's kind of worked around for the reset stuff, because there are two
layers to that: the mdio device layer reset support which knows nothing
of the PHY binding state to the network driver, and the phylib reset
support, but it is not nice.

Regulators are reference counted so if the hwmon driver enables it
using mdio_device_power_on() it will stay on even after the PHY driver
calls phy_device_power_off(), right? Am I missing something?

If that is true, you will need to audit the PHY drivers to add that.

This change doesn't have any effect on devices which don't have a
regulator assigned in DT though. The one I'm adding in the last patch
is the first to use this.

Bart