The blsp_dma controller is shared between the different subsystems,
which is why it is already initialized by the firmware. We should not
reinitialize it from Linux to avoid potential other users of the DMA
engine to misbehave.
In mainline this can be described using the "qcom,controlled-remotely"
property. In the downstream/vendor kernel from Qualcomm there is an
opposite "qcom,managed-locally" property. This property is *not* set
for the qcom,sps-dma@7884000 so adding "qcom,controlled-remotely"
upstream matches the behavior of the downstream/vendor kernel.
Adding this seems to fix some weird issues with UART where both
input/output becomes garbled with certain obscure firmware versions on
some devices.
Signed-off-by: Stephan Gerhold <[email protected]>
---
Stephan Gerhold (2):
arm64: dts: qcom: msm8916: Make blsp_dma controlled-remotely
arm64: dts: qcom: msm8939: Make blsp_dma controlled-remotely
arch/arm64/boot/dts/qcom/msm8916.dtsi | 1 +
arch/arm64/boot/dts/qcom/msm8939.dtsi | 1 +
2 files changed, 2 insertions(+)
---
base-commit: adcad44bd1c73a5264bff525e334e2f6fc01bb9b
change-id: 20231204-msm8916-blsp-dma-remote-516df8aac521
Best regards,
--
Stephan Gerhold <[email protected]>
The blsp_dma controller is shared between the different subsystems,
which is why it is already initialized by the firmware. We should not
reinitialize it from Linux to avoid potential other users of the DMA
engine to misbehave.
In mainline this can be described using the "qcom,controlled-remotely"
property. In the downstream/vendor kernel from Qualcomm there is an
opposite "qcom,managed-locally" property. This property is *not* set
for the qcom,sps-dma@7884000 [1] so adding "qcom,controlled-remotely"
upstream matches the behavior of the downstream/vendor kernel.
Adding this seems to fix some weird issues with UART where both
input/output becomes garbled with certain obscure firmware versions on
some devices.
[1]: https://git.codelinaro.org/clo/la/kernel/msm-3.10/-/blob/LA.BR.1.2.9.1-02310-8x16.0/arch/arm/boot/dts/qcom/msm8916.dtsi#L1466-1472
Cc: <[email protected]> # 6.5
Fixes: a0e5fb103150 ("arm64: dts: qcom: Add msm8916 BLSP device nodes")
Signed-off-by: Stephan Gerhold <[email protected]>
---
This should only be backported to v6.5+ since it depends on commit
8975dd41a9db ("dmaengine: qcom: bam_dma: allow omitting
num-{channels,ees}") which landed in v6.5.
---
arch/arm64/boot/dts/qcom/msm8916.dtsi | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm64/boot/dts/qcom/msm8916.dtsi b/arch/arm64/boot/dts/qcom/msm8916.dtsi
index e8a14dd7e7c2..7f8327b0dbdb 100644
--- a/arch/arm64/boot/dts/qcom/msm8916.dtsi
+++ b/arch/arm64/boot/dts/qcom/msm8916.dtsi
@@ -2155,6 +2155,7 @@ blsp_dma: dma-controller@7884000 {
clock-names = "bam_clk";
#dma-cells = <1>;
qcom,ee = <0>;
+ qcom,controlled-remotely;
};
blsp_uart1: serial@78af000 {
--
2.43.0
The blsp_dma controller is shared between the different subsystems,
which is why it is already initialized by the firmware. We should not
reinitialize it from Linux to avoid potential other users of the DMA
engine to misbehave.
In mainline this can be described using the "qcom,controlled-remotely"
property. In the downstream/vendor kernel from Qualcomm there is an
opposite "qcom,managed-locally" property. This property is *not* set
for the qcom,sps-dma@7884000 [1] so adding "qcom,controlled-remotely"
upstream matches the behavior of the downstream/vendor kernel.
Adding this seems to fix some weird issues with UART where both
input/output becomes garbled with certain obscure firmware versions on
some devices.
[1]: https://git.codelinaro.org/clo/la/kernel/msm-3.10/-/blob/LA.BR.1.2.9.1-02310-8x16.0/arch/arm/boot/dts/qcom/msm8939-common.dtsi#L866-872
Cc: <[email protected]> # 6.5
Fixes: 61550c6c156c ("arm64: dts: qcom: Add msm8939 SoC")
Signed-off-by: Stephan Gerhold <[email protected]>
---
This should only be backported to v6.5+ since it depends on commit
8975dd41a9db ("dmaengine: qcom: bam_dma: allow omitting
num-{channels,ees}") which landed in v6.5.
---
arch/arm64/boot/dts/qcom/msm8939.dtsi | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm64/boot/dts/qcom/msm8939.dtsi b/arch/arm64/boot/dts/qcom/msm8939.dtsi
index 95610a32750a..9eb8f1ceee99 100644
--- a/arch/arm64/boot/dts/qcom/msm8939.dtsi
+++ b/arch/arm64/boot/dts/qcom/msm8939.dtsi
@@ -1761,6 +1761,7 @@ blsp_dma: dma-controller@7884000 {
clock-names = "bam_clk";
#dma-cells = <1>;
qcom,ee = <0>;
+ qcom,controlled-remotely;
};
blsp_uart1: serial@78af000 {
--
2.43.0
On 04/12/2023 11:21, Stephan Gerhold wrote:
> The blsp_dma controller is shared between the different subsystems,
> which is why it is already initialized by the firmware. We should not
> reinitialize it from Linux to avoid potential other users of the DMA
> engine to misbehave.
>
> In mainline this can be described using the "qcom,controlled-remotely"
> property. In the downstream/vendor kernel from Qualcomm there is an
> opposite "qcom,managed-locally" property. This property is *not* set
> for the qcom,sps-dma@7884000 [1] so adding "qcom,controlled-remotely"
> upstream matches the behavior of the downstream/vendor kernel.
>
> Adding this seems to fix some weird issues with UART where both
> input/output becomes garbled with certain obscure firmware versions on
> some devices.
>
> [1]: https://git.codelinaro.org/clo/la/kernel/msm-3.10/-/blob/LA.BR.1.2.9.1-02310-8x16.0/arch/arm/boot/dts/qcom/msm8939-common.dtsi#L866-872
>
> Cc: <[email protected]> # 6.5
> Fixes: 61550c6c156c ("arm64: dts: qcom: Add msm8939 SoC")
> Signed-off-by: Stephan Gerhold <[email protected]>
> ---
> This should only be backported to v6.5+ since it depends on commit
> 8975dd41a9db ("dmaengine: qcom: bam_dma: allow omitting
> num-{channels,ees}") which landed in v6.5.
> ---
> arch/arm64/boot/dts/qcom/msm8939.dtsi | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm64/boot/dts/qcom/msm8939.dtsi b/arch/arm64/boot/dts/qcom/msm8939.dtsi
> index 95610a32750a..9eb8f1ceee99 100644
> --- a/arch/arm64/boot/dts/qcom/msm8939.dtsi
> +++ b/arch/arm64/boot/dts/qcom/msm8939.dtsi
> @@ -1761,6 +1761,7 @@ blsp_dma: dma-controller@7884000 {
> clock-names = "bam_clk";
> #dma-cells = <1>;
> qcom,ee = <0>;
> + qcom,controlled-remotely;
> };
>
> blsp_uart1: serial@78af000 {
>
Reviewed-by: Bryan O'Donoghue <[email protected]>
On 04/12/2023 11:21, Stephan Gerhold wrote:
> The blsp_dma controller is shared between the different subsystems,
> which is why it is already initialized by the firmware. We should not
> reinitialize it from Linux to avoid potential other users of the DMA
> engine to misbehave.
>
> In mainline this can be described using the "qcom,controlled-remotely"
> property. In the downstream/vendor kernel from Qualcomm there is an
> opposite "qcom,managed-locally" property. This property is *not* set
> for the qcom,sps-dma@7884000 [1] so adding "qcom,controlled-remotely"
> upstream matches the behavior of the downstream/vendor kernel.
>
> Adding this seems to fix some weird issues with UART where both
> input/output becomes garbled with certain obscure firmware versions on
> some devices.
>
> [1]: https://git.codelinaro.org/clo/la/kernel/msm-3.10/-/blob/LA.BR.1.2.9.1-02310-8x16.0/arch/arm/boot/dts/qcom/msm8916.dtsi#L1466-1472
>
> Cc: <[email protected]> # 6.5
> Fixes: a0e5fb103150 ("arm64: dts: qcom: Add msm8916 BLSP device nodes")
> Signed-off-by: Stephan Gerhold <[email protected]>
> ---
> This should only be backported to v6.5+ since it depends on commit
> 8975dd41a9db ("dmaengine: qcom: bam_dma: allow omitting
> num-{channels,ees}") which landed in v6.5.
> ---
> arch/arm64/boot/dts/qcom/msm8916.dtsi | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm64/boot/dts/qcom/msm8916.dtsi b/arch/arm64/boot/dts/qcom/msm8916.dtsi
> index e8a14dd7e7c2..7f8327b0dbdb 100644
> --- a/arch/arm64/boot/dts/qcom/msm8916.dtsi
> +++ b/arch/arm64/boot/dts/qcom/msm8916.dtsi
> @@ -2155,6 +2155,7 @@ blsp_dma: dma-controller@7884000 {
> clock-names = "bam_clk";
> #dma-cells = <1>;
> qcom,ee = <0>;
> + qcom,controlled-remotely;
> };
>
> blsp_uart1: serial@78af000 {
>
Reviewed-by: Bryan O'Donoghue <[email protected]>
On Mon, 04 Dec 2023 11:21:19 +0100, Stephan Gerhold wrote:
> The blsp_dma controller is shared between the different subsystems,
> which is why it is already initialized by the firmware. We should not
> reinitialize it from Linux to avoid potential other users of the DMA
> engine to misbehave.
>
> In mainline this can be described using the "qcom,controlled-remotely"
> property. In the downstream/vendor kernel from Qualcomm there is an
> opposite "qcom,managed-locally" property. This property is *not* set
> for the qcom,sps-dma@7884000 so adding "qcom,controlled-remotely"
> upstream matches the behavior of the downstream/vendor kernel.
>
> [...]
Applied, thanks!
[1/2] arm64: dts: qcom: msm8916: Make blsp_dma controlled-remotely
commit: 7c45b6ddbcff01f9934d11802010cfeb0879e693
[2/2] arm64: dts: qcom: msm8939: Make blsp_dma controlled-remotely
commit: 4bbda9421f316efdaef5dbf642e24925ef7de130
Best regards,
--
Bjorn Andersson <[email protected]>