On 11/27/2025 1:00 PM, Krzysztof Kozlowski wrote:
On Wed, Nov 26, 2025 at 03:15:42PM +0530, Kumari Pallavi wrote:
Add a new compatible string "qcom,kaanapali-fastrpc" to support
for Kaanapali SoC.
... and here you write WHY or provide background about hardware
differences, instead of writing what you did. We see what you did easily
- we can read the diff. Additionally your subject already said this, so
basically your commit msg is redundant...
I still do not know why Kaanapali needs this.
Thank you for the feedback. Let me clarify the hardware differences that
require this change:
Kaanapali introduces a new DSP IOVA formatting scheme and a hardware
revision in CDSP that expands the DMA addressable range. On previous
SoCs, DSPs used a 32-bit physical address plus a 4-bit Stream ID (SID).
Kaanapali changes:
SID placement: The SID field moves within the physical address, so the
driver must know the new sid_pos to correctly form IOVA for ADSP/CDSP.
Expanded DMA range: CDSP now supports a 34-bit physical address plus the
4-bit SID, requiring an updated DMA mask to avoid truncating valid
addresses.
To apply these changes only on Kaanapali, I introduce a SoC-specific
compatible string "qcom,kaanapali-fastrpc".
Older DTs using "qcom,fastrpc" remain valid and unchanged; the new
behavior is applied only when the Kaanapali-specific compatible is present.
https://lore.kernel.org/all/[email protected]/
Signed-off-by: Kumari Pallavi <[email protected]>
---
Documentation/devicetree/bindings/misc/qcom,fastrpc.yaml | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/misc/qcom,fastrpc.yaml
b/Documentation/devicetree/bindings/misc/qcom,fastrpc.yaml
index 3f6199fc9ae6..6c19217d63a6 100644
--- a/Documentation/devicetree/bindings/misc/qcom,fastrpc.yaml
+++ b/Documentation/devicetree/bindings/misc/qcom,fastrpc.yaml
@@ -18,7 +18,10 @@ description: |
properties:
compatible:
- const: qcom,fastrpc
+ items:
No need to introduce items, wasn't here before. Just enum directly.
If I use enum directly, the schema will only validate a single
string—either "qcom,fastrpc" or "qcom,kaanapali-fastrpc". However, my
DTS changes introduce a compatible property with two strings: the
SoC-specific string followed by the generic fallback.
That’s why I used items in the schema—to allow an array of strings where
the first entry is "qcom,kaanapali-fastrpc" and the second is "qcom,fastrpc"
Thanks,
Pallavi>> + - enum:
+ - qcom,kaanapali-fastrpc
+ - qcom,fastrpc
label:
enum:
--
2.34.1
