| Message ID | 20230616081440.v2.3.Ic62daa649b47b656b313551d646c4de9a7da4bd4@changeid (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | a54b7fa6b9ab6b4ecb7d9aba6b1a0ce1bcc961e3 |
| Headers | show |
| Series | [v2,1/4] dt-bindings: firmware: qcom,scm: Document that SCM can be dma-coherent | expand |
diff --git a/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi b/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi index ca6920de7ea8..1472e7f10831 100644 --- a/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi +++ b/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi @@ -892,6 +892,11 @@ &remoteproc_mpss { qcom,spare-regs = <&tcsr_regs_2 0xb3e4>; }; +&scm { + /* TF-A firmware maps memory cached so mark dma-coherent to match. */ + dma-coherent; +}; + &sdhc_1 { status = "okay";
Trogdor devices use firmware backed by TF-A instead of Qualcomm's normal TZ. On TF-A we end up mapping memory as cacheable. 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-cacheable. 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") Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org> Signed-off-by: Douglas Anderson <dianders@chromium.org> --- Changes in v2: - Add comment in dts. - Moved scm node out of pinctrl section to the proper place. arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi | 5 +++++ 1 file changed, 5 insertions(+)