2023-07-13 17:10:45

by Amit Pundir

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Subject: [PATCH v5 2/2] arm64: dts: qcom: sdm845-db845c: Mark cont splash memory region as reserved

Adding a reserved memory region for the framebuffer memory
(the splash memory region set up by the bootloader).

Signed-off-by: Amit Pundir <[email protected]>
---
v5: Re-sending with updated dt-bindings patch in mdss-common
schema.

v4: Re-sending this along with a new dt-bindings patch to
document memory-region property in qcom,sdm845-mdss
schema and keep dtbs_check happy.

v3: Point this reserved region to MDSS.

v2: Updated commit message.

There was some dicussion on v1 but it didn't go anywhere,
https://lore.kernel.org/linux-kernel/[email protected]/T/#u.
The general consensus is that this memory should be freed and be
made resuable but that (releasing this piece of memory) has been
tried before and it is not trivial to return the reserved memory
node to the system RAM pool in this case.

arch/arm64/boot/dts/qcom/sdm845-db845c.dts | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/sdm845-db845c.dts b/arch/arm64/boot/dts/qcom/sdm845-db845c.dts
index d6b464cb61d6..f546f6f57c1e 100644
--- a/arch/arm64/boot/dts/qcom/sdm845-db845c.dts
+++ b/arch/arm64/boot/dts/qcom/sdm845-db845c.dts
@@ -101,6 +101,14 @@ hdmi_con: endpoint {
};
};

+ reserved-memory {
+ /* Cont splash region set up by the bootloader */
+ cont_splash_mem: framebuffer@9d400000 {
+ reg = <0x0 0x9d400000 0x0 0x2400000>;
+ no-map;
+ };
+ };
+
lt9611_1v8: lt9611-vdd18-regulator {
compatible = "regulator-fixed";
regulator-name = "LT9611_1V8";
@@ -506,6 +514,7 @@ &i2c14 {
};

&mdss {
+ memory-region = <&cont_splash_mem>;
status = "okay";
};

--
2.25.1



2023-07-14 19:39:26

by Caleb Connolly

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Subject: Re: [PATCH v5 2/2] arm64: dts: qcom: sdm845-db845c: Mark cont splash memory region as reserved



On 13/07/2023 17:52, Amit Pundir wrote:
> Adding a reserved memory region for the framebuffer memory
> (the splash memory region set up by the bootloader).
>
> Signed-off-by: Amit Pundir <[email protected]>

Reviewed-by: Caleb Connolly <[email protected]>
> ---
> v5: Re-sending with updated dt-bindings patch in mdss-common
> schema.
>
> v4: Re-sending this along with a new dt-bindings patch to
> document memory-region property in qcom,sdm845-mdss
> schema and keep dtbs_check happy.
>
> v3: Point this reserved region to MDSS.
>
> v2: Updated commit message.
>
> There was some dicussion on v1 but it didn't go anywhere,
> https://lore.kernel.org/linux-kernel/[email protected]/T/#u.
> The general consensus is that this memory should be freed and be
> made resuable but that (releasing this piece of memory) has been
> tried before and it is not trivial to return the reserved memory
> node to the system RAM pool in this case.
>
> arch/arm64/boot/dts/qcom/sdm845-db845c.dts | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/qcom/sdm845-db845c.dts b/arch/arm64/boot/dts/qcom/sdm845-db845c.dts
> index d6b464cb61d6..f546f6f57c1e 100644
> --- a/arch/arm64/boot/dts/qcom/sdm845-db845c.dts
> +++ b/arch/arm64/boot/dts/qcom/sdm845-db845c.dts
> @@ -101,6 +101,14 @@ hdmi_con: endpoint {
> };
> };
>
> + reserved-memory {
> + /* Cont splash region set up by the bootloader */
> + cont_splash_mem: framebuffer@9d400000 {
> + reg = <0x0 0x9d400000 0x0 0x2400000>;
> + no-map;
> + };
> + };
> +
> lt9611_1v8: lt9611-vdd18-regulator {
> compatible = "regulator-fixed";
> regulator-name = "LT9611_1V8";
> @@ -506,6 +514,7 @@ &i2c14 {
> };
>
> &mdss {
> + memory-region = <&cont_splash_mem>;
> status = "okay";
> };
>

--
// Caleb (they/them)

2023-07-26 12:15:58

by Krzysztof Kozlowski

[permalink] [raw]
Subject: Re: [PATCH v5 2/2] arm64: dts: qcom: sdm845-db845c: Mark cont splash memory region as reserved

On 13/07/2023 18:52, Amit Pundir wrote:
> Adding a reserved memory region for the framebuffer memory
> (the splash memory region set up by the bootloader).
>
> Signed-off-by: Amit Pundir <[email protected]>
> ---

I think your commit msg misses describing the actual problem, impact to
users and finally cc-stable.

Best regards,
Krzysztof