[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <9c0506a6f654f72ea62fed864c1b2a26@walle.cc>
Date: Tue, 06 Dec 2022 09:29:15 +0100
From: Michael Walle <michael@...le.cc>
To: Rob Herring <robh@...nel.org>
Cc: Xu Liang <lxu@...linear.com>, Andrew Lunn <andrew@...n.ch>,
Heiner Kallweit <hkallweit1@...il.com>,
Russell King <linux@...linux.org.uk>,
"David S . Miller" <davem@...emloft.net>,
Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
devicetree@...r.kernel.org
Subject: Re: [PATCH net-next v1 3/4] dt-bindings: net: phy: add MaxLinear
GPY2xx bindings
Am 2022-12-05 22:53, schrieb Michael Walle:
> Am 2022-12-05 22:29, schrieb Rob Herring:
>> On Fri, Dec 02, 2022 at 04:12:03PM +0100, Michael Walle wrote:
>>> Add the device tree bindings for the MaxLinear GPY2xx PHYs.
>>>
>>> Signed-off-by: Michael Walle <michael@...le.cc>
>>> ---
>>>
>>> Is the filename ok? I was unsure because that flag is only for the
>>> GPY215
>>> for now. But it might also apply to others. Also there is no
>>> compatible
>>> string, so..
>>>
>>> .../bindings/net/maxlinear,gpy2xx.yaml | 47
>>> +++++++++++++++++++
>>> 1 file changed, 47 insertions(+)
>>> create mode 100644
>>> Documentation/devicetree/bindings/net/maxlinear,gpy2xx.yaml
>>>
>>> diff --git
>>> a/Documentation/devicetree/bindings/net/maxlinear,gpy2xx.yaml
>>> b/Documentation/devicetree/bindings/net/maxlinear,gpy2xx.yaml
>>> new file mode 100644
>>> index 000000000000..d71fa9de2b64
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/net/maxlinear,gpy2xx.yaml
>>> @@ -0,0 +1,47 @@
>>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
>>> +%YAML 1.2
>>> +---
>>> +$id: http://devicetree.org/schemas/net/maxlinear,gpy2xx.yaml#
>>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>>> +
>>> +title: MaxLinear GPY2xx PHY
>>> +
>>> +maintainers:
>>> + - Andrew Lunn <andrew@...n.ch>
>>> + - Michael Walle <michael@...le.cc>
>>> +
>>> +allOf:
>>> + - $ref: ethernet-phy.yaml#
>>> +
>>> +properties:
>>> + maxlinear,use-broken-interrupts:
>>> + description: |
>>> + Interrupts are broken on some GPY2xx PHYs in that they keep
>>> the
>>> + interrupt line asserted even after the interrupt status
>>> register is
>>> + cleared. Thus it is blocking the interrupt line which is
>>> usually bad
>>> + for shared lines. By default interrupts are disabled for this
>>> PHY and
>>> + polling mode is used. If one can live with the consequences,
>>> this
>>> + property can be used to enable interrupt handling.
>>
>> Just omit the interrupt property if you don't want interrupts and add
>> it
>> if you do.
>
> How does that work together with "the device tree describes
> the hardware and not the configuration". The interrupt line
> is there, its just broken sometimes and thus it's disabled
> by default for these PHY revisions/firmwares. With this
> flag the user can say, "hey on this hardware it is not
> relevant because we don't have shared interrupts or because
> I know what I'm doing".
Specifically you can't do the following: Have the same device
tree and still being able to use it with a future PHY firmware
update/revision. Because according to your suggestion, this
won't have the interrupt property set. With this flag you can
have the following cases:
(1) the interrupt information is there and can be used in the
future by non-broken PHY revisions,
(2) broken PHYs will ignore the interrupt line
(3) except the system designer opts-in with this flag (because
maybe this is the only PHY on the interrupt line etc).
-michael
Powered by blists - more mailing lists