2022-10-17 13:36:21

by Sai Krishna Potthuri

[permalink] [raw]
Subject: [PATCH v2 2/2] Revert "dt-bindings: pinctrl-zynqmp: Add output-enable configuration"

This reverts commit 133ad0d9af99bdca90705dadd8d31c20bfc9919f.

On systems with older PMUFW (Xilinx ZynqMP Platform Management Firmware)
using these pinctrl properties can cause system hang because there is
missing feature autodetection.
When this feature is implemented, support for these two properties should
bring back.

Cc: [email protected]
Signed-off-by: Sai Krishna Potthuri <[email protected]>
---
.../devicetree/bindings/pinctrl/xlnx,zynqmp-pinctrl.yaml | 4 ----
1 file changed, 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/pinctrl/xlnx,zynqmp-pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/xlnx,zynqmp-pinctrl.yaml
index 1e2b9b627b12..2722dc7bb03d 100644
--- a/Documentation/devicetree/bindings/pinctrl/xlnx,zynqmp-pinctrl.yaml
+++ b/Documentation/devicetree/bindings/pinctrl/xlnx,zynqmp-pinctrl.yaml
@@ -274,10 +274,6 @@ patternProperties:
slew-rate:
enum: [0, 1]

- output-enable:
- description:
- This will internally disable the tri-state for MIO pins.
-
drive-strength:
description:
Selects the drive strength for MIO pins, in mA.
--
2.17.1


2022-10-21 01:32:52

by Rob Herring

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Subject: Re: [PATCH v2 2/2] Revert "dt-bindings: pinctrl-zynqmp: Add output-enable configuration"

On Mon, Oct 17, 2022 at 06:33:03PM +0530, Sai Krishna Potthuri wrote:
> This reverts commit 133ad0d9af99bdca90705dadd8d31c20bfc9919f.
>
> On systems with older PMUFW (Xilinx ZynqMP Platform Management Firmware)
> using these pinctrl properties can cause system hang because there is
> missing feature autodetection.
> When this feature is implemented, support for these two properties should
> bring back.

So I'm going to get to review the revert of the revert at some point?
Why do the properties need to be removed from the binding? They work on
'not older' firmware, right? Isn't just removing the driver support or
removing from .dts files enough?

Rob

2022-10-21 07:38:33

by Michal Simek

[permalink] [raw]
Subject: Re: [PATCH v2 2/2] Revert "dt-bindings: pinctrl-zynqmp: Add output-enable configuration"

Hi Rob,

On 10/21/22 03:11, Rob Herring wrote:
> On Mon, Oct 17, 2022 at 06:33:03PM +0530, Sai Krishna Potthuri wrote:
>> This reverts commit 133ad0d9af99bdca90705dadd8d31c20bfc9919f.
>>
>> On systems with older PMUFW (Xilinx ZynqMP Platform Management Firmware)
>> using these pinctrl properties can cause system hang because there is
>> missing feature autodetection.
>> When this feature is implemented, support for these two properties should
>> bring back.
>
> So I'm going to get to review the revert of the revert at some point?
> Why do the properties need to be removed from the binding? They work on
> 'not older' firmware, right? Isn't just removing the driver support or
> removing from .dts files enough?

Removing functionality should be IMHO enough. Maybe make sense to inform users
that there is missing functionality where they define these properties via DT.

Thanks,
Michal