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Documentation: dt: Explicitly mark Samsung Exynos SoC bindings as unstable

PATCH New Marek Szyprowski 6 participants 6 messages Dec 16, 2016 – Dec 21, 2016

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#0 lore raw

PATCH 1/1 Documentation: dt: Explicitly mark Samsung Exynos SoC bindings as unstable

Samsung Exynos SoCs and boards related bindings evolved since the initial introduction, but initially the bindings were minimal and a bit incomplete (they never described all the hardware modules available in the SoCs). Since then some significant (not fully compatible) changes have been already committed a few times (like gpio replaced by pinctrl, display ddc, mfc reserved memory, some core clocks added to various hardware modules, added more required nodes).

On the other side there are no boards which have device tree embedded in the bootloader. Device tree blob is always compiled from the kernel tree and updated together with the kernel image.

Thus to avoid further adding a bunch of workarounds for old/missing bindings and allow to make cleanup of the existing code and device tree files, lets mark Samsung Exynos SoC platform bindings as unstable. This means that bindings can may change at any time and users should use the dtb file compiled from the same kernel source tree as the kernel image.

---
 Documentation/devicetree/bindings/arm/samsung/exynos.txt | 12 ++++++++++++
 1 file changed, 12 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/samsung/exynos.txt
Documentation/devicetree/bindings/arm/samsung/exynos.txt new file +12 -0
new file mode 100644
index 000000000000..0c606f4c6e85
@@ -0,0 +1,12 @@
+Samsung Exynos SoC Family Device Tree Bindings
+---------------------------------------------------------------
+
+Work in progress statement:
+
+Device tree files and bindings applying to Samsung Exynos SoCs and boards are
+considered "unstable". Any Samsung Exynos device tree binding may change at any
+time. Be sure to use a device tree binary and a kernel image generated from the
+same source tree.
+
+Please refer to Documentation/devicetree/bindings/ABI.txt for a definition of a
+stable binding/ABI.
Signature · 1 line
1.9.1
#1 lore raw

PATCH 1/1 Documentation: dt: Explicitly mark Samsung Exynos SoC bindings as unstable

Hello Marek,

Quoted 12 lines · Marek Szyprowski

Samsung Exynos SoCs and boards related bindings evolved since the initial introduction, but initially the bindings were minimal and a bit incomplete (they never described all the hardware modules available in the SoCs). Since then some significant (not fully compatible) changes have been already committed a few times (like gpio replaced by pinctrl, display ddc, mfc reserved memory, some core clocks added to various hardware modules, added more required nodes).

On the other side there are no boards which have device tree embedded in the bootloader. Device tree blob is always compiled from the kernel tree and updated together with the kernel image.

Quoted 8 lines

Thus to avoid further adding a bunch of workarounds for old/missing bindings and allow to make cleanup of the existing code and device tree files, lets mark Samsung Exynos SoC platform bindings as unstable. This means that bindings can may change at any time and users should use the dtb file compiled from the same kernel source tree as the kernel image.

---

I completely agree with you on this.

Signature · 3 lines
Javier Martinez Canillas
Open Source Group
Samsung Research America
#2 lore raw

PATCH 1/1 Documentation: dt: Explicitly mark Samsung Exynos SoC bindings as unstable

In reply to Marek Szyprowski

Hi,

Quoted 12 lines · Marek Szyprowski

Samsung Exynos SoCs and boards related bindings evolved since the initial introduction, but initially the bindings were minimal and a bit incomplete (they never described all the hardware modules available in the SoCs). Since then some significant (not fully compatible) changes have been already committed a few times (like gpio replaced by pinctrl, display ddc, mfc reserved memory, some core clocks added to various hardware modules, added more required nodes).

On the other side there are no boards which have device tree embedded in the bootloader. Device tree blob is always compiled from the kernel tree and updated together with the kernel image.

Quoted 7 lines

Thus to avoid further adding a bunch of workarounds for old/missing bindings and allow to make cleanup of the existing code and device tree files, lets mark Samsung Exynos SoC platform bindings as unstable. This means that bindings can may change at any time and users should use the dtb file compiled from the same kernel source tree as the kernel image.

This change is long overdue..

Quoted 13 lines
---
 Documentation/devicetree/bindings/arm/samsung/exynos.txt | 12 ++++++++++++
 1 file changed, 12 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/samsung/exynos.txt
Documentation/devicetree/bindings/arm/samsung/exynos.txt new file +2 -0
new file mode 100644
index 000000000000..0c606f4c6e85
@@ -0,0 +1,12 @@
+Samsung Exynos SoC Family Device Tree Bindings
+---------------------------------------------------------------

Documentation/devicetree/bindings/arm/samsung/exynos.txt line 12

Quoted 10 lines
Documentation/devicetree/bindings/arm/samsung/exynos.txt new file +10 -0
+
+Work in progress statement:
+
+Device tree files and bindings applying to Samsung Exynos SoCs and boards are
+considered "unstable". Any Samsung Exynos device tree binding may change at any
+time. Be sure to use a device tree binary and a kernel image generated from the
+same source tree.
+
+Please refer to Documentation/devicetree/bindings/ABI.txt for a definition of a
+stable binding/ABI.

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics

#3 lore raw

PATCH 1/1 Documentation: dt: Explicitly mark Samsung Exynos SoC bindings as unstable

In reply to Marek Szyprowski

Hi Marek,

Quoted 12 lines · Marek Szyprowski

Samsung Exynos SoCs and boards related bindings evolved since the initial introduction, but initially the bindings were minimal and a bit incomplete (they never described all the hardware modules available in the SoCs). Since then some significant (not fully compatible) changes have been already committed a few times (like gpio replaced by pinctrl, display ddc, mfc reserved memory, some core clocks added to various hardware modules, added more required nodes).

On the other side there are no boards which have device tree embedded in the bootloader. Device tree blob is always compiled from the kernel tree and updated together with the kernel image.

Quoted 8 lines

Thus to avoid further adding a bunch of workarounds for old/missing bindings and allow to make cleanup of the existing code and device tree files, lets mark Samsung Exynos SoC platform bindings as unstable. This means that bindings can may change at any time and users should use the dtb file compiled from the same kernel source tree as the kernel image.

---

I agree with you. This is very much required. It's not only about new bindings, we are facing problems in adopting existing bindings as well (e.g scu), to make exynos support completely DT based and simplify our code base.

I expect and foresee requirements of many more such changes in very near future.

Thanks,
Pankaj Dubey

#4 lore raw

PATCH 1/1 Documentation: dt: Explicitly mark Samsung Exynos SoC bindings as unstable

In reply to Marek Szyprowski
Quoted 12 lines · Marek Szyprowski

Samsung Exynos SoCs and boards related bindings evolved since the initial introduction, but initially the bindings were minimal and a bit incomplete (they never described all the hardware modules available in the SoCs). Since then some significant (not fully compatible) changes have been already committed a few times (like gpio replaced by pinctrl, display ddc, mfc reserved memory, some core clocks added to various hardware modules, added more required nodes).

On the other side there are no boards which have device tree embedded in the bootloader. Device tree blob is always compiled from the kernel tree and updated together with the kernel image.

Quoted 5 lines

Thus to avoid further adding a bunch of workarounds for old/missing bindings and allow to make cleanup of the existing code and device tree files, lets mark Samsung Exynos SoC platform bindings as unstable. This means that bindings can may change at any time and users should use the dtb file compiled from the same kernel source tree as the kernel image.

I agree but please re-send it after merge window. This is not the best time to start discussions about it.

Best regards,
Krzysztof

maintainer
#5 lore raw

PATCH 1/1 Documentation: dt: Explicitly mark Samsung Exynos SoC bindings as unstable

In reply to Marek Szyprowski
Quoted 12 lines · Marek Szyprowski

Samsung Exynos SoCs and boards related bindings evolved since the initial introduction, but initially the bindings were minimal and a bit incomplete (they never described all the hardware modules available in the SoCs). Since then some significant (not fully compatible) changes have been already committed a few times (like gpio replaced by pinctrl, display ddc, mfc reserved memory, some core clocks added to various hardware modules, added more required nodes).

On the other side there are no boards which have device tree embedded in the bootloader. Device tree blob is always compiled from the kernel tree and updated together with the kernel image.

Quoted 5 lines

Thus to avoid further adding a bunch of workarounds for old/missing bindings and allow to make cleanup of the existing code and device tree files, lets mark Samsung Exynos SoC platform bindings as unstable. This means that bindings can may change at any time and users should use the dtb file compiled from the same kernel source tree as the kernel image.

I'd like this to be more explicit about which bindings in particular are not considered stable (or which ones are). "exynos" covers lots of things.

I'll still complain if commit messages don't say explicitly that the commit breaks compatibility and why that is okay.

Rob