[PATCH v2 4/4] arm64: dts: qcom: sc7280: Mark SCM as dma-coherent for chrome devices

[Douglas Anderson]

Just like for sc7180 devices using the Chrome bootflow (AKA trogdor
and IDP), sc7280 devices using the Chrome bootflow also need their
firmware marked dma-coherent. On sc7280 this wasn't causing WiFi to
fail to startup, since WiFi works differently there. However, on
sc7280 devices we were still getting the message at bootup after
commit 7bd6680b47fa ("Revert "Revert "arm64: dma: Drop cache
invalidation from arch_dma_prep_coherent()"""):

 qcom_scm firmware:scm: Assign memory protection call failed -22
 qcom_rmtfs_mem 9c900000.memory: assign memory failed
 qcom_rmtfs_mem: probe of 9c900000.memory failed with error -22

We should mark SCM properly just like we did for trogdor.

Fixes: 7bd6680b47fa ("Revert "Revert "arm64: dma: Drop cache invalidation from arch_dma_prep_coherent()""")
Fixes: 7a1f4e7f740d ("arm64: dts: qcom: sc7280: Add basic dts/dtsi files for sc7280 soc")
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
---
I marked this as "Fixes" for the patch that first added the SCM node
to sc7280. Given all the reorganization of the files it wouldn't be
all that easy to really backport it to there, but that should be
OK. Things seemed to work fine before commit 7bd6680b47fa ("Revert
"Revert "arm64: dma: Drop cache invalidation from
arch_dma_prep_coherent()""") anyway.

Changes in v2:
- sc7280 patch new for v2.

 arch/arm64/boot/dts/qcom/sc7280-chrome-common.dtsi | 5 +++++
 arch/arm64/boot/dts/qcom/sc7280.dtsi               | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/sc7280-chrome-common.dtsi b/arch/arm64/boot/dts/qcom/sc7280-chrome-common.dtsi
index f562e4d2b655..2e1cd219fc18 100644
--- a/arch/arm64/boot/dts/qcom/sc7280-chrome-common.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7280-chrome-common.dtsi
@@ -79,6 +79,11 @@ &remoteproc_wpss {
 	firmware-name = "ath11k/WCN6750/hw1.0/wpss.mdt";
 };
 
+&scm {
+	/* TF-A firmware maps memory cached so mark dma-coherent to match. */
+	dma-coherent;
+};
+
 &wifi {
 	status = "okay";
 
diff --git a/arch/arm64/boot/dts/qcom/sc7280.dtsi b/arch/arm64/boot/dts/qcom/sc7280.dtsi
index 2fd1d3c0eb34..36f0bb9b3cbb 100644
--- a/arch/arm64/boot/dts/qcom/sc7280.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7280.dtsi
@@ -656,7 +656,7 @@ memory@80000000 {
 	};
 
 	firmware {
-		scm {
+		scm: scm {
 			compatible = "qcom,scm-sc7280", "qcom,scm";
 		};
 	};
-- 
2.41.0.162.gfafddb0af9-goog