On 12/14/22 01:11, Krzysztof Kozlowski wrote:
On 13/12/2022 15:07, Sibi Sankar wrote:Update the bindings to reflect the addition of the new modem metadata carveout reference to the memory-region property. Signed-off-by: Sibi Sankar <quic_sibis@xxxxxxxxxxx> --- .../devicetree/bindings/remoteproc/qcom,sc7180-mss-pil.yaml | 3 ++- .../devicetree/bindings/remoteproc/qcom,sc7280-mss-pil.yaml | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/Documentation/devicetree/bindings/remoteproc/qcom,sc7180-mss-pil.yaml b/Documentation/devicetree/bindings/remoteproc/qcom,sc7180-mss-pil.yaml index e4a7da8020f4..b1402bef0ebe 100644 --- a/Documentation/devicetree/bindings/remoteproc/qcom,sc7180-mss-pil.yaml +++ b/Documentation/devicetree/bindings/remoteproc/qcom,sc7180-mss-pil.yaml @@ -95,6 +95,7 @@ properties: items: - description: MBA reserved region - description: modem reserved region + - description: metadata reserved regionWhich makes the third item now required, also for all out of tree DTS and other users of the bindings. Please write a bit more in commit msg why this is necessary (e.g. was it broken before?). I assume the driver does not break the ABI?
I'll pad the commit msg with some of the additional info from patch 4. commit c44094eee32f "arm64: dma: Drop cache invalidation from arch_dma_prep_coherent()" exposed a bug in the driver affecting SoCs from msm8996 on wards. The application processor accessing the dynamically allocated region after giving control to the modem results in a XPU violation. The recommended fix was to use a no-map carveout instead and memunmap before giving control to the modem. The future kernels that are paired with an older dtbs would crash during modem bootup since we would continue to use dma_alloc_attr. But all the other combinations (old kernel/new dtb) will continue to work. - Sibi
Best regards, Krzysztof
