* [PATCH] arm64: dts: imx8mq: Set the correct gpu_ahb clock frequency
@ 2026-01-24 13:55 Sebastian Krzyszkowiak
2026-01-26 18:14 ` Frank Li
2026-01-27 18:27 ` Fabio Estevam
0 siblings, 2 replies; 5+ messages in thread
From: Sebastian Krzyszkowiak @ 2026-01-24 13:55 UTC (permalink / raw)
To: Rob Herring, Krzysztof Kozlowski, Conor Dooley, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam
Cc: devicetree, imx, linux-arm-kernel, linux-kernel, kernel,
Sebastian Krzyszkowiak
According to i.MX 8M Quad Reference Manual, GPU_AHB_CLK_ROOT's maximum
frequency is 400MHz.
Signed-off-by: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm>
---
arch/arm64/boot/dts/freescale/imx8mq.dtsi | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/boot/dts/freescale/imx8mq.dtsi b/arch/arm64/boot/dts/freescale/imx8mq.dtsi
index 607962f807be..6a25e219832c 100644
--- a/arch/arm64/boot/dts/freescale/imx8mq.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mq.dtsi
@@ -1632,7 +1632,7 @@ gpu: gpu@38000000 {
<&clk IMX8MQ_GPU_PLL_OUT>,
<&clk IMX8MQ_GPU_PLL>;
assigned-clock-rates = <800000000>, <800000000>,
- <800000000>, <800000000>, <0>;
+ <800000000>, <400000000>, <0>;
power-domains = <&pgc_gpu>;
};
---
base-commit: 24d479d26b25bce5faea3ddd9fa8f3a6c3129ea7
change-id: 20260105-imx8mq-gpu-ahb-clock-139ba9ca9a6c
Best regards,
--
Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm>
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] arm64: dts: imx8mq: Set the correct gpu_ahb clock frequency
2026-01-24 13:55 [PATCH] arm64: dts: imx8mq: Set the correct gpu_ahb clock frequency Sebastian Krzyszkowiak
@ 2026-01-26 18:14 ` Frank Li
2026-01-26 20:10 ` Sebastian Krzyszkowiak
2026-01-27 18:27 ` Fabio Estevam
1 sibling, 1 reply; 5+ messages in thread
From: Frank Li @ 2026-01-26 18:14 UTC (permalink / raw)
To: Sebastian Krzyszkowiak
Cc: Rob Herring, Krzysztof Kozlowski, Conor Dooley, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam, devicetree,
imx, linux-arm-kernel, linux-kernel, kernel
On Sat, Jan 24, 2026 at 02:55:48PM +0100, Sebastian Krzyszkowiak wrote:
> According to i.MX 8M Quad Reference Manual, GPU_AHB_CLK_ROOT's maximum
> frequency is 400MHz.
I checked datasheet
Nominal mode—the maximum
GPU frequency supported in
this mode is 800 MHz.
Does difference grade (industry vs consumer) impact max frequency?
Frank
>
> Signed-off-by: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm>
> ---
> arch/arm64/boot/dts/freescale/imx8mq.dtsi | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm64/boot/dts/freescale/imx8mq.dtsi b/arch/arm64/boot/dts/freescale/imx8mq.dtsi
> index 607962f807be..6a25e219832c 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mq.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mq.dtsi
> @@ -1632,7 +1632,7 @@ gpu: gpu@38000000 {
> <&clk IMX8MQ_GPU_PLL_OUT>,
> <&clk IMX8MQ_GPU_PLL>;
> assigned-clock-rates = <800000000>, <800000000>,
> - <800000000>, <800000000>, <0>;
> + <800000000>, <400000000>, <0>;
> power-domains = <&pgc_gpu>;
> };
>
>
> ---
> base-commit: 24d479d26b25bce5faea3ddd9fa8f3a6c3129ea7
> change-id: 20260105-imx8mq-gpu-ahb-clock-139ba9ca9a6c
>
> Best regards,
> --
> Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm>
>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] arm64: dts: imx8mq: Set the correct gpu_ahb clock frequency
2026-01-26 18:14 ` Frank Li
@ 2026-01-26 20:10 ` Sebastian Krzyszkowiak
2026-01-27 18:25 ` Frank Li
0 siblings, 1 reply; 5+ messages in thread
From: Sebastian Krzyszkowiak @ 2026-01-26 20:10 UTC (permalink / raw)
To: Frank Li
Cc: Rob Herring, Krzysztof Kozlowski, Conor Dooley, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam, devicetree,
imx, linux-arm-kernel, linux-kernel, kernel
On poniedziałek, 26 stycznia 2026 19:14:55 czas środkowoeuropejski standardowy
Frank Li wrote:
> On Sat, Jan 24, 2026 at 02:55:48PM +0100, Sebastian Krzyszkowiak wrote:
> > According to i.MX 8M Quad Reference Manual, GPU_AHB_CLK_ROOT's maximum
> > frequency is 400MHz.
>
> I checked datasheet
>
> Nominal mode—the maximum
> GPU frequency supported in
> this mode is 800 MHz.
>
> Does difference grade (industry vs consumer) impact max frequency?
No. That sentence relates to GPU_SHADER_CLK_ROOT, which can go up to 1000 MHz,
but requires "overdrive mode" (higher voltage) when above 800 MHz. It's set to
800 MHz in the device tree at the moment.
This patch changes GPU_AHB_CLK_ROOT, which has absolute maximum of 400 MHz
(see section 5.1.2 Table 5-1).
> Frank
>
> > Signed-off-by: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm>
> > ---
> >
> > arch/arm64/boot/dts/freescale/imx8mq.dtsi | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch/arm64/boot/dts/freescale/imx8mq.dtsi
> > b/arch/arm64/boot/dts/freescale/imx8mq.dtsi index
> > 607962f807be..6a25e219832c 100644
> > --- a/arch/arm64/boot/dts/freescale/imx8mq.dtsi
> > +++ b/arch/arm64/boot/dts/freescale/imx8mq.dtsi
> > @@ -1632,7 +1632,7 @@ gpu: gpu@38000000 {
> >
> > <&clk
IMX8MQ_GPU_PLL_OUT>,
> > <&clk
IMX8MQ_GPU_PLL>;
> >
> > assigned-clock-rates = <800000000>,
<800000000>,
> >
> > - <800000000>,
<800000000>, <0>;
> > + <800000000>,
<400000000>, <0>;
> >
> > power-domains = <&pgc_gpu>;
> >
> > };
> >
> > ---
> > base-commit: 24d479d26b25bce5faea3ddd9fa8f3a6c3129ea7
> > change-id: 20260105-imx8mq-gpu-ahb-clock-139ba9ca9a6c
> >
> > Best regards,
> > --
> > Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] arm64: dts: imx8mq: Set the correct gpu_ahb clock frequency
2026-01-26 20:10 ` Sebastian Krzyszkowiak
@ 2026-01-27 18:25 ` Frank Li
0 siblings, 0 replies; 5+ messages in thread
From: Frank Li @ 2026-01-27 18:25 UTC (permalink / raw)
To: Sebastian Krzyszkowiak
Cc: Rob Herring, Krzysztof Kozlowski, Conor Dooley, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam, devicetree,
imx, linux-arm-kernel, linux-kernel, kernel
On Mon, Jan 26, 2026 at 09:10:37PM +0100, Sebastian Krzyszkowiak wrote:
> On poniedziałek, 26 stycznia 2026 19:14:55 czas środkowoeuropejski standardowy
> Frank Li wrote:
> > On Sat, Jan 24, 2026 at 02:55:48PM +0100, Sebastian Krzyszkowiak wrote:
> > > According to i.MX 8M Quad Reference Manual, GPU_AHB_CLK_ROOT's maximum
> > > frequency is 400MHz.
> >
> > I checked datasheet
> >
> > Nominal mode—the maximum
> > GPU frequency supported in
> > this mode is 800 MHz.
> >
> > Does difference grade (industry vs consumer) impact max frequency?
>
> No. That sentence relates to GPU_SHADER_CLK_ROOT, which can go up to 1000 MHz,
> but requires "overdrive mode" (higher voltage) when above 800 MHz. It's set to
> 800 MHz in the device tree at the moment.
>
> This patch changes GPU_AHB_CLK_ROOT, which has absolute maximum of 400 MHz
> (see section 5.1.2 Table 5-1).
Yes!
Reviewed-by: Frank Li <Frank.Li@nxp.com>
>
> > Frank
> >
> > > Signed-off-by: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm>
> > > ---
> > >
> > > arch/arm64/boot/dts/freescale/imx8mq.dtsi | 2 +-
> > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/arch/arm64/boot/dts/freescale/imx8mq.dtsi
> > > b/arch/arm64/boot/dts/freescale/imx8mq.dtsi index
> > > 607962f807be..6a25e219832c 100644
> > > --- a/arch/arm64/boot/dts/freescale/imx8mq.dtsi
> > > +++ b/arch/arm64/boot/dts/freescale/imx8mq.dtsi
> > > @@ -1632,7 +1632,7 @@ gpu: gpu@38000000 {
> > >
> > > <&clk
> IMX8MQ_GPU_PLL_OUT>,
> > > <&clk
> IMX8MQ_GPU_PLL>;
> > >
> > > assigned-clock-rates = <800000000>,
> <800000000>,
> > >
> > > - <800000000>,
> <800000000>, <0>;
> > > + <800000000>,
> <400000000>, <0>;
> > >
> > > power-domains = <&pgc_gpu>;
> > >
> > > };
> > >
> > > ---
> > > base-commit: 24d479d26b25bce5faea3ddd9fa8f3a6c3129ea7
> > > change-id: 20260105-imx8mq-gpu-ahb-clock-139ba9ca9a6c
> > >
> > > Best regards,
> > > --
> > > Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm>
>
>
>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] arm64: dts: imx8mq: Set the correct gpu_ahb clock frequency
2026-01-24 13:55 [PATCH] arm64: dts: imx8mq: Set the correct gpu_ahb clock frequency Sebastian Krzyszkowiak
2026-01-26 18:14 ` Frank Li
@ 2026-01-27 18:27 ` Fabio Estevam
1 sibling, 0 replies; 5+ messages in thread
From: Fabio Estevam @ 2026-01-27 18:27 UTC (permalink / raw)
To: Sebastian Krzyszkowiak
Cc: Rob Herring, Krzysztof Kozlowski, Conor Dooley, Shawn Guo,
Sascha Hauer, Pengutronix Kernel Team, devicetree, imx,
linux-arm-kernel, linux-kernel, kernel
On Sat, Jan 24, 2026 at 10:56 AM Sebastian Krzyszkowiak
<sebastian.krzyszkowiak@puri.sm> wrote:
>
> According to i.MX 8M Quad Reference Manual, GPU_AHB_CLK_ROOT's maximum
> frequency is 400MHz.
>
> Signed-off-by: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm>
Shouldn't this have a Fixes tag?
^ permalink raw reply [flat|nested] 5+ messages in thread
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2026-01-24 13:55 [PATCH] arm64: dts: imx8mq: Set the correct gpu_ahb clock frequency Sebastian Krzyszkowiak
2026-01-26 18:14 ` Frank Li
2026-01-26 20:10 ` Sebastian Krzyszkowiak
2026-01-27 18:25 ` Frank Li
2026-01-27 18:27 ` Fabio Estevam
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