Trogdor devices use firmware backed by TF-A instead of Qualcomm's
normal TZ. On TF-A we end up mapping memory as cachable. Specifically,
you can see in Trogdor's TF-A code [1] in qti_sip_mem_assign() that we
call qti_mmap_add_dynamic_region() with MT_RO_DATA. This translates
down to MT_MEMORY instead of MT_NON_CACHEABLE or MT_DEVICE. Apparently
Qualcomm's normal TZ implementation maps the memory as non-cachable.
Let's add the "dma-coherent" attribute to the SCM for trogdor.
Adding "dma-coherent" like this fixes WiFi on sc7180-trogdor
devices. WiFi was broken as of commit 7bd6680b47fa ("Revert "Revert
"arm64: dma: Drop cache invalidation from
arch_dma_prep_coherent()"""). Specifically at bootup we'd get:
qcom_scm firmware:scm: Assign memory protection call failed -22
qcom_rmtfs_mem 94600000.memory: assign memory failed
qcom_rmtfs_mem: probe of 94600000.memory failed with error -22
>From discussion on the mailing lists [2] and over IRC [3], it was
determined that we should always have been tagging the SCM as
dma-coherent on trogdor but that the old "invalidate" happened to make
things work most of the time. Tagging it properly like this is a much
more robust solution.
[1] https://chromium.googlesource.com/chromiumos/third_party/arm-trusted-firmware/+/refs/heads/firmware-trogdor-13577.B/plat/qti/common/src/qti_syscall.c
[2] https://lore.kernel.org/r/20230614165904.1.I279773c37e2c1ed8fbb622ca6d1397aea0023526@changeid
[3] https://oftc.irclog.whitequark.org/linux-msm/2023-06-15
Fixes: 7bd6680b47fa ("Revert "Revert "arm64: dma: Drop cache invalidation from arch_dma_prep_coherent()""")
Fixes: 7ec3e67307f8 ("arm64: dts: qcom: sc7180-trogdor: add initial trogdor and lazor dt")
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
---
arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi | 4 ++++
arch/arm64/boot/dts/qcom/sc7180.dtsi | 2 +-
2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi b/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
index ca6920de7ea8..5e1e7c5bd474 100644
--- a/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
@@ -1194,6 +1194,10 @@ &pm6150l_gpios {
"";
};
+&scm {
+ dma-coherent;
+};
+
&tlmm {
/*
* pinctrl settings for pins that have no real owners.
diff --git a/arch/arm64/boot/dts/qcom/sc7180.dtsi b/arch/arm64/boot/dts/qcom/sc7180.dtsi
index f479cab8ab45..a65be760d1a7 100644
--- a/arch/arm64/boot/dts/qcom/sc7180.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7180.dtsi
@@ -369,7 +369,7 @@ CLUSTER_SLEEP_0: cluster-sleep-0 {
};
firmware {
- scm {
+ scm: scm {
compatible = "qcom,scm-sc7180", "qcom,scm";
};
};
--
2.41.0.162.gfafddb0af9-goog
