Re: [PATCH v2 1/4] dt-bindings: firmware: qcom,scm: Add minidump SRAM property

[Mukesh Ojha]

On Fri, May 22, 2026 at 11:15:22AM +0200, Krzysztof Kozlowski wrote:
> On 22/05/2026 09:52, Mukesh Ojha wrote:
> > On Wed, May 20, 2026 at 12:17:21PM +0200, Krzysztof Kozlowski wrote:
> >> On Tue, May 19, 2026 at 10:44:39PM +0530, Mukesh Ojha wrote:
> >>> On most Qualcomm SoCs where minidump is supported, a word in always-on
> >>> SRAM is shared between the kernel and boot firmware. Before DDR is
> >>> initialised on the warm reset following a crash, firmware reads this
> >>> word to decide if minidump is enabled and collect a minidump and where
> >>>  to deliver it (USB upload to a host, or save to local storage).
> >>>
> >>> Add a 'sram' property to the SCM binding to describe a region in
> >>> always-on SRAM where the minidump download destination value could be
> >>> written. Boot firmware reads it before DDR is initialised on a warm
> >>> reset to decide where to store the minidump either to host PC or to
> >>> on device storage.
> >>>
> >>> Signed-off-by: Mukesh Ojha <mukesh.ojha@xxxxxxxxxxxxxxxx>
> >>> ---
> >>>  .../devicetree/bindings/firmware/qcom,scm.yaml   | 16 ++++++++++++++++
> >>>  1 file changed, 16 insertions(+)
> >>>
> >>> diff --git a/Documentation/devicetree/bindings/firmware/qcom,scm.yaml b/Documentation/devicetree/bindings/firmware/qcom,scm.yaml
> >>> index 25f62bacbc91..27422d00b8fc 100644
> >>> --- a/Documentation/devicetree/bindings/firmware/qcom,scm.yaml
> >>> +++ b/Documentation/devicetree/bindings/firmware/qcom,scm.yaml
> >>> @@ -129,6 +129,13 @@ properties:
> >>>            - description: offset of the download mode control register
> >>>      description: TCSR hardware block
> >>>  
> >>> +  sram:
> >>> +    description:
> >>> +      Phandle to a region in always-on SRAM used to store the download
> >>> +      mode value for boot firmware to read before DDR is initialised on
> >>> +      the next warm reset.
> >>> +    maxItems: 1
> >>> +
> >>>  allOf:
> >>>    # Clocks
> >>>    - if:
> >>> @@ -250,3 +257,12 @@ examples:
> >>>              clock-names = "core", "bus", "iface";
> >>>          };
> >>>      };
> >>> +
> >>> +  - |
> >>> +    firmware {
> >>> +        scm {
> >>> +            compatible = "qcom,scm-kaanapali", "qcom,scm";
> >>
> >> Incomplete, missing interrupts.
> > 
> > Interrupt number comes from firmware and has not even been described
> > statically for SCM  for any SoC and so I am not sure to include it in
> > the example. Perhaps I took the wrong example here and should have taken
> > some pre-Gunyah Qualcomm SoC.
> 
> Then you do not need a new example. Difference in one property (reset
> cells) does not justify new example.

Sure, will drop it.
> 
> Best regards,
> Krzysztof

-- 
-Mukesh Ojha