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[v7,2/3] DT/arm,gic-v3-its: add reset-on-suspend property

Message ID 20180301054820.42847-3-dbasehore@chromium.org (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Derek Basehore March 1, 2018, 5:48 a.m. UTC
This adds documentation for the new reset-on-suspend property. This
property enables saving and restoring the ITS for when it loses state
in system suspend.

Signed-off-by: Derek Basehore <dbasehore@chromium.org>
---
 .../devicetree/bindings/interrupt-controller/arm,gic-v3.txt  | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Mark Rutland March 1, 2018, 11:34 a.m. UTC | #1
On Wed, Feb 28, 2018 at 09:48:19PM -0800, Derek Basehore wrote:
> This adds documentation for the new reset-on-suspend property. This
> property enables saving and restoring the ITS for when it loses state
> in system suspend.
> 
> Signed-off-by: Derek Basehore <dbasehore@chromium.org>
> ---
>  .../devicetree/bindings/interrupt-controller/arm,gic-v3.txt  | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt b/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt
> index 0a57f2f4167d..dfd1b9b838cd 100644
> --- a/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt
> +++ b/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt
> @@ -78,6 +78,11 @@ These nodes must have the following properties:
>  Optional:
>  - socionext,synquacer-pre-its: (u32, u32) tuple describing the untranslated
>    address and size of the pre-ITS window.
> +- reset-on-suspend: Boolean property. Indicates that the ITS loses power
> +  on suspend to memory (via PSCI_SYSTEM_SUSPEND). Registers and data within
> +  the ITS will be the same as before probe (PSCI FW does not restore state).

What does 'before probe' mean? Perhaps 'at reset'?

Is the state well-defined, or might there be some bits that differ from
boot-to-boot?

Otherwise, this generally looks ok.

> +  Any state stored in external memory is maintained (such as collection
> +  tables stored in external memory).

This a property of PSCI_SYSTEM_SUSPEND not corrupting memory state, so
this need not be stated here. This can go.

Thanks,
Mark.
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt b/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt
index 0a57f2f4167d..dfd1b9b838cd 100644
--- a/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt
+++ b/Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt
@@ -78,6 +78,11 @@  These nodes must have the following properties:
 Optional:
 - socionext,synquacer-pre-its: (u32, u32) tuple describing the untranslated
   address and size of the pre-ITS window.
+- reset-on-suspend: Boolean property. Indicates that the ITS loses power
+  on suspend to memory (via PSCI_SYSTEM_SUSPEND). Registers and data within
+  the ITS will be the same as before probe (PSCI FW does not restore state).
+  Any state stored in external memory is maintained (such as collection
+  tables stored in external memory).
 
 The main GIC node must contain the appropriate #address-cells,
 #size-cells and ranges properties for the reg property of all ITS